{"title":"MK-677 (Ibutamoren)","description":"\u003cp\u003eMK-677, also known as ibutamoren, ibutamoren mesylate, MK-0677, L-163,191 and Nutrobal, is a non-peptide growth hormone secretagogue: an orally active small molecule that acts as an agonist at the ghrelin receptor, GHS-R1a. This page lists every brand of MK-677 stocked at Free Muscle, our own Janoshik batch-tested capsules alongside iMuscle, Yakka Strength and Thoroughbred Labs, compared on strength per capsule, pack size and batch testing. Everything here is supplied for laboratory research only, to adults aged 18 or over.\u003c\/p\u003e\n\n\u003ch2\u003eWhat is MK-677?\u003c\/h2\u003e\n\u003cp\u003eMK-677 belongs to the growth hormone secretagogue class. It was developed at Merck in the 1990s as an orally available, non-peptide mimic of the growth hormone releasing peptides such as GHRP-6, which are only active by injection. It binds and activates the growth hormone secretagogue receptor (GHS-R1a) in the pituitary and hypothalamus, the same receptor that the stomach hormone ghrelin acts on. In trial participants, this amplified the pulsatile release of growth hormone and raised circulating insulin-like growth factor 1 (IGF-1) levels.\u003c\/p\u003e\n\u003cp\u003eIt is worth being precise about what MK-677 is not. It is not a SARM, not an anabolic steroid, not a peptide and it contains no growth hormone. It is unusual among research compounds sold in the UK in having a substantial published human trial record, including studies in older adults, obese men, patients recovering from hip fracture and patients with Alzheimer disease. Despite that record, it was never approved as a medicine anywhere in the world, and clinical development was discontinued.\u003c\/p\u003e\n\n\u003ch2\u003eWhat the published research reports\u003c\/h2\u003e\n\u003cp\u003eIn a two-year randomised, placebo-controlled trial in 65 healthy adults aged 60 to 81 (Nass et al., 2008), MK-677 raised growth hormone and IGF-1 into the range seen in young adults. Fat-free mass rose by about 1.1 kg in the MK-677 group against a fall of 0.5 kg on placebo, and body weight rose by 2.7 kg against 0.8 kg. Abdominal visceral fat and total fat mass did not change, but limb fat increased more in the treated group. Fasting glucose rose, insulin sensitivity fell, cortisol increased, and the most frequent side effects were increased appetite, transient lower-limb oedema and muscle pain. The extra fat-free mass did not translate into any change in strength or function.\u003c\/p\u003e\n\u003cp\u003eIn an eight-week trial in 24 obese men (Svensson et al., 1998), serum IGF-1 rose by roughly 40 per cent and fat-free mass increased, while total and visceral fat were unchanged. Basal metabolic rate rose at two weeks but not at eight, and an oral glucose tolerance test showed impaired glucose handling at both time points.\u003c\/p\u003e\n\u003cp\u003eA phase IIb study in 123 elderly patients recovering from hip fracture (Adunsky et al., 2011) found that IGF-1 rose but most functional measures did not improve. The trial was terminated early because of a safety signal of congestive heart failure in a small number of patients, and the authors concluded that the compound had an unfavourable safety profile in that population.\u003c\/p\u003e\n\u003cp\u003eNone of these findings is a claim about the products listed on this page. They describe what was measured in specific trial populations under medical supervision, and they include the adverse findings for a reason.\u003c\/p\u003e\n\n\u003ch2\u003eBrands of MK-677 we stock\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eFree Muscle MK-677 Ibutamoren\u003c\/strong\u003e: our own brand, capsules, 60 per bottle, in three strengths: \u003ca href=\"\/products\/mk-677-ibutamoren-10mg\"\u003e10mg\u003c\/a\u003e, \u003ca href=\"\/products\/mk-677-ibutamoren-12-5mg\"\u003e12.5mg\u003c\/a\u003e and \u003ca href=\"\/products\/mk-677-ibutamoren-25mg\"\u003e25mg\u003c\/a\u003e. Every batch is assayed for identity and purity by Janoshik Analytical, with the Certificate of Analysis sent on request. The three strengths have their own page at \u003ca href=\"\/collections\/mk-677-ibutamoren\"\u003eFree Muscle MK-677 Ibutamoren\u003c\/a\u003e.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e\u003ca href=\"\/products\/imuscle-ibutamoren-mk-677-60-10mg\"\u003eiMuscle Ibutamoren MK-677\u003c\/a\u003e\u003c\/strong\u003e: 10mg per capsule, 60 capsules, 600mg total per pack. A COA is shown where iMuscle supplies one for the batch we hold.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e\u003ca href=\"\/products\/yakka-strength-yakka-strength-mk677\"\u003eYakka Strength MK-677\u003c\/a\u003e\u003c\/strong\u003e: 60 capsules. The strength per capsule is stated on the product listing where the manufacturer declares it. A COA is shown where Yakka Strength supplies one for the batch we hold.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e\u003ca href=\"\/products\/thoroughbred-labs-mk677\"\u003eThoroughbred Labs MK-677\u003c\/a\u003e\u003c\/strong\u003e: 60 capsules. Check the listing for the declared strength. A COA is shown where Thoroughbred Labs supplies one for the batch we hold.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e\u003ca href=\"\/products\/mk-777-acetamoren-bioreactive-series\"\u003eMK-777 (Acetamoren) Bioreactive Series\u003c\/a\u003e\u003c\/strong\u003e: a Free Muscle product designation from our Bioreactive Series, 60 capsules, Janoshik batch-tested. MK-777 is not a name found in the published pharmacological literature, so it is compared on its own page at \u003ca href=\"\/collections\/mk-777\"\u003eMK-777\u003c\/a\u003e rather than treated as an MK-677 equivalent.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e\u003ca href=\"\/products\/christmas-bulking-bundle\"\u003eResearch Bundle: MK-677 + RAD-140 + YK-11\u003c\/a\u003e\u003c\/strong\u003e: a Free Muscle bundle of three separate research compounds in one parcel. Each item in it is batch-tested individually.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eHow to compare them\u003c\/h3\u003e\n\u003cp\u003eTwo bottles of 60 capsules can contain very different quantities of compound. Multiply the strength per capsule by the number of capsules to get total milligrams per pack: 10mg x 60 is 600mg, 12.5mg x 60 is 750mg, 25mg x 60 is 1,500mg. Divide the price on the listing by that total to get a cost per milligram, which is the only like-for-like comparison between brands. Then check whether a batch certificate exists for the exact batch on the label, because an untested 25mg capsule is not worth more than a tested 10mg one. Our article \u003ca href=\"\/blogs\/news\/mk-677-brands-compared\"\u003eMK-677 by brand\u003c\/a\u003e walks through the same arithmetic.\u003c\/p\u003e\n\n\u003ch2\u003eBatch testing and certificates of analysis\u003c\/h2\u003e\n\u003cp\u003eA Certificate of Analysis (COA) is a laboratory report on one specific batch. For MK-677 it should show the identity of the compound (usually by HPLC or mass spectrometry against a reference standard), the measured purity as a percentage, the batch number, the date of testing and the name of the laboratory. Every Free Muscle brand batch is assayed by Janoshik Analytical, an independent laboratory; email us with the batch number printed on your label and we send the certificate for that batch. For iMuscle, Yakka Strength and Thoroughbred Labs, a COA is shown on the listing only where the manufacturer supplies one for the batch we hold. A generic PDF with no batch number, or a certificate for a batch that is not the one in your hand, is marketing rather than evidence. See \u003ca href=\"\/pages\/lab-tests\"\u003ehow we test\u003c\/a\u003e and \u003ca href=\"\/blogs\/news\/how-to-read-a-certificate-of-analysis\"\u003ehow to read a COA\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003ch2\u003eLegal status in the UK\u003c\/h2\u003e\n\u003cp\u003eMK-677 is not a licensed medicine in the UK and has no marketing authorisation from the MHRA. It is not an authorised food supplement or novel food, and it cannot be sold for human consumption. Free Muscle supplies it as a research compound for laboratory use only, to customers aged 18 or over. Growth hormone secretagogues, including ibutamoren, are prohibited at all times under section S2 of the WADA Prohibited List, so it is not compatible with drug-tested sport. Full detail is on our \u003ca href=\"\/pages\/mk-677-legal-status-uk\"\u003eMK-677 legal status in the UK\u003c\/a\u003e page.\u003c\/p\u003e\n\n\u003ch2\u003eStorage and handling\u003c\/h2\u003e\n\u003cp\u003eKeep capsules in the original sealed container, in a cool, dry place away from direct light and heat. Reseal after opening and do not decant into unlabelled containers. Keep out of the reach of children and pets. Handle in line with normal laboratory good practice, record the batch number for any work you carry out, and dispose of unwanted material responsibly.\u003c\/p\u003e\n\n\u003ch2\u003eDelivery and returns\u003c\/h2\u003e\n\u003cp\u003eFree Muscle is a UK company (FreeMuscle LTD, Scunthorpe). Every order ships with free tracked UK delivery in plain packaging, and orders placed before 2pm Monday to Friday are processed the same working day. EU delivery takes 3 to 7 working days. Unopened items can be returned within 30 days. See \u003ca href=\"\/pages\/shipping\"\u003edelivery\u003c\/a\u003e and our \u003ca href=\"\/pages\/guarantee\"\u003e30-day guarantee\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003ch2\u003eRelated reading\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\u003ca href=\"\/blogs\/news\/mk-677-ibutamoren-what-the-research-says\"\u003eMK-677 (Ibutamoren): What the Research Says\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/blogs\/news\/mk-677-brands-compared\"\u003eMK-677 by brand: what actually differs when the molecule is the same\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/blogs\/news\/price-per-mg-compare-sarms-peptides\"\u003ePrice per milligram: the only honest way to compare SARMs and peptides\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/blogs\/news\/what-is-janoshik-analytical\"\u003eWhat Is Janoshik Analytical? Third-Party Testing Explained\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/blogs\/news\/what-are-sarms-the-2026-research-guide\"\u003eWhat Are SARMs? The 2026 Research Guide\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul\u003e\n\u003cli\u003e\u003ca href=\"\/collections\/mk-677-ibutamoren\"\u003eFree Muscle MK-677 Ibutamoren (10mg, 12.5mg, 25mg)\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/collections\/mk-777\"\u003eMK-777 (Acetamoren)\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/collections\/ipamorelin\"\u003eIpamorelin\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/collections\/sarms\"\u003eSARMs\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cem\u003eAll MK-677 products on this page are sold for laboratory research use only. They are not licensed medicines, have not been evaluated by the MHRA, EMA or FDA, and are not for human consumption. Customers must be 18 or over. Nothing on this page is medical advice or dosing guidance.\u003c\/em\u003e\u003c\/p\u003e","products":[{"product_id":"mk-677-ibutamoren-25mg","title":"MK-677 Ibutamoren — 25mg · 60 Capsules","description":"\u003cp\u003e\u003cstrong\u003eMK-677 (Ibutamoren) — 25mg × 60 capsules.\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eIbutamoren is a growth hormone secretagogue: an agonist at the ghrelin (GHS-R1a) receptor. It has published human trial data, which is unusual in this category, but development as a medicine was never completed and it is \u003cstrong\u003enot authorised as a medicine or a food supplement in the UK or EU\u003c\/strong\u003e. It is on the WADA Prohibited List and is detectable.\u003c\/p\u003e\u003cp\u003eKnown effects reported in trials include increased appetite, water retention and raised blood glucose. We do not publish dosing schedules, cycle lengths or post-cycle protocols for human use.\u003c\/p\u003e\u003cp\u003eWhat we do verify: identity and purity, per batch, by Janoshik Analytical — an independent laboratory we neither own nor control. The batch number is printed on the pack; email it to us and we will send that batch's Certificate of Analysis. You do not need to have bought anything to ask.\u003c\/p\u003e\u003cp\u003e\u003csmall\u003e\u003cstrong\u003eResearch use only.\u003c\/strong\u003e Not a medicine or dietary supplement, not evaluated by the MHRA, EMA or FDA, not for human consumption. Nothing on this page is medical advice.\u003c\/small\u003e\u003c\/p\u003e","brand":"FreeMuscle","offers":[{"title":"Default Title","offer_id":46856631550178,"sku":"10000014","price":69.99,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0772\/3499\/5426\/files\/openart-image_nIMXU6ba_1760816509377_raw.jpg?v=1766262315"},{"product_id":"mk-677-ibutamoren-10mg","title":"MK-677 Ibutamoren — 10mg · 60 Capsules","description":"\u003cp\u003e\u003cstrong\u003eMK-677 (Ibutamoren) — 10mg × 60 capsules.\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eIbutamoren is a growth hormone secretagogue: an agonist at the ghrelin (GHS-R1a) receptor. It has published human trial data, but development as a medicine was never completed and it is \u003cstrong\u003enot authorised as a medicine or a food supplement in the UK or EU\u003c\/strong\u003e. It is on the WADA Prohibited List and is detectable.\u003c\/p\u003e\u003cp\u003eThe only difference between our 10mg, 12.5mg and 25mg is the amount per capsule. We do not recommend a strength, because that would be dosing advice for a compound sold for research use only.\u003c\/p\u003e\u003cp\u003eIdentity and purity are verified per batch by Janoshik Analytical, an independent laboratory. Certificate of Analysis available on request.\u003c\/p\u003e\u003cp\u003e\u003csmall\u003e\u003cstrong\u003eResearch use only.\u003c\/strong\u003e Not a medicine or dietary supplement, not evaluated by the MHRA, EMA or FDA, not for human consumption.\u003c\/small\u003e\u003c\/p\u003e","brand":"FreeMuscle","offers":[{"title":"Default Title","offer_id":46856695185634,"sku":"10000013","price":49.99,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0772\/3499\/5426\/files\/openart-image_Z_Qi57Md_1760817219254_raw.jpg?v=1766262333"},{"product_id":"mk-677-ibutamoren-12-5mg","title":"MK-677 Ibutamoren — 12.5mg · 60 Capsules","description":"\u003cp\u003e\u003cstrong\u003eMK-677 (Ibutamoren) — 12.5mg × 60 capsules.\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eIbutamoren is a growth hormone secretagogue: an agonist at the ghrelin (GHS-R1a) receptor. It has published human trial data, but development as a medicine was never completed and it is \u003cstrong\u003enot authorised as a medicine or a food supplement in the UK or EU\u003c\/strong\u003e. It is on the WADA Prohibited List and is detectable.\u003c\/p\u003e\u003cp\u003eThe only difference between our 10mg, 12.5mg and 25mg is the amount per capsule. We do not recommend a strength, because that would be dosing advice for a compound sold for research use only.\u003c\/p\u003e\u003cp\u003eIdentity and purity are verified per batch by Janoshik Analytical, an independent laboratory. Certificate of Analysis available on request.\u003c\/p\u003e\u003cp\u003e\u003csmall\u003e\u003cstrong\u003eResearch use only.\u003c\/strong\u003e Not a medicine or dietary supplement, not evaluated by the MHRA, EMA or FDA, not for human consumption.\u003c\/small\u003e\u003c\/p\u003e","brand":"FreeMuscle","offers":[{"title":"Default Title","offer_id":46961071292642,"sku":"10000001","price":44.99,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0772\/3499\/5426\/files\/mk.webp?v=1766262843"},{"product_id":"mk-777-acetamoren-bioreactive-series","title":"MK-777 (Acetamoren) — Bioreactive Series","description":"\u003cp\u003e\u003cstrong\u003eMK-777 (Acetamoren) — Bioreactive Series.\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003e\"MK-777 (Acetamoren)\" is Free Muscle's own product designation for a growth hormone secretagogue acting at the GHS-R1a (ghrelin) receptor. It is not a name you will find in the published pharmacological literature, and there are no human clinical trials under that designation. If published research matters to you, MK-677 (ibutamoren) is the compound in this class that has it.\u003c\/p\u003e\u003cp\u003eIt is \u003cstrong\u003enot authorised as a medicine or a food supplement in the UK or EU\u003c\/strong\u003e, and growth hormone secretagogues are on the WADA Prohibited List.\u003c\/p\u003e\u003cp\u003eIdentity and purity are verified per batch by Janoshik Analytical, an independent laboratory. Certificate of Analysis available on request. We do not publish dosing schedules or post-cycle protocols for human use.\u003c\/p\u003e\u003cp\u003e\u003csmall\u003e\u003cstrong\u003eResearch use only.\u003c\/strong\u003e Not a medicine or dietary supplement, not evaluated by the MHRA, EMA or FDA, not for human consumption.\u003c\/small\u003e\u003c\/p\u003e","brand":"FreeMuscle","offers":[{"title":"Default Title","offer_id":47040793280738,"sku":"10000003","price":69.99,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0772\/3499\/5426\/files\/openart-image_qYBx60sy_1763246601208_raw.jpg?v=1766262710"},{"product_id":"imuscle-ibutamoren-mk-677-60-10mg","title":"iMuscle Ibutamoren MK-677 — 60 caps, 10mg","description":"\u003cp\u003eiMuscle Ibutamoren MK-677 is supplied as 60 capsules stated at 10 mg each, a total of 600 mg of MK-677 per pack. MK-677, also called ibutamoren, L-163,191 or Nutrobal, is an oral growth hormone secretagogue with a genuine human trial record. iMuscle manufactures the product and Free Muscle stocks it through the \u003ca href=\"\/pages\/muscle-market\"\u003eMuscle Market\u003c\/a\u003e range for laboratory research by adults aged 18 and over.\u003c\/p\u003e\u003ch2\u003eAbout MK-677\u003c\/h2\u003e\u003cp\u003eMK-677, or ibutamoren, is an orally active ghrelin mimetic developed by Merck under the code L-163,191, a synthetic small molecule rather than a peptide. It binds the GHS-R1a receptor in the hypothalamus and pituitary, prompting pulsatile growth hormone release and a sustained rise in IGF-1. PubChem lists the free base as CID 178024, CAS 159634-47-6, formula C27H36N4O5S, molecular weight 528.7.\u003c\/p\u003e\u003ch3\u003eWhat the published research reports\u003c\/h3\u003e\u003cp\u003eThe human literature is real but limited. In 1996 Chapman and colleagues reported that daily oral MK-677 in 32 healthy elderly volunteers, randomised against placebo, increased growth hormone pulse amplitude and raised IGF-1. Sampling every 20 minutes for 24 hours showed higher pulses and higher troughs between them, with no change in the number of pulses. IGF-binding protein 3 and fasting glucose rose; cortisol did not change. The study lasted four weeks at most and measured hormones only.\u003c\/p\u003e\u003cp\u003eSvensson and colleagues then randomised 24 otherwise healthy obese men aged 18 to 50 to MK-677 or placebo for eight weeks (Svensson et al., 1998). IGF-1 rose by about 40 per cent with MK-677, significantly more than with placebo, and fat-free mass increased, while total and visceral fat did not change significantly. Basal metabolic rate was higher at two weeks but not significantly at eight, and an oral glucose tolerance test showed impaired glucose handling at both points although fasting glucose was unchanged.\u003c\/p\u003e\u003cp\u003eThe longest trial followed 65 healthy adults aged 60 to 81 for up to two years, with its main end points at twelve months (Nass et al., 2008). Fat-free mass went up by an average of 1.1 kg on MK-677 and drifted down by 0.5 kg on placebo, but strength, physical function and abdominal visceral fat did not differ, and limb fat grew more. Increased appetite, oedema, muscle pain, reduced insulin sensitivity, a small rise in fasting glucose, higher cortisol and greater weight gain were recorded. The authors judged the study too small and too short to assess function.\u003c\/p\u003e\u003cp\u003eAcross the three trials, higher growth hormone and IGF-1 came with poorer glucose handling, and the one trial that measured strength and function found no change in either. MK-677 was never approved as a medicine. Nothing in these studies is a claim about this listing.\u003c\/p\u003e\u003ch2\u003eThis listing\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eCompound: MK-677 (Ibutamoren)\u003c\/li\u003e\n\u003cli\u003eBrand: iMuscle\u003c\/li\u003e\n\u003cli\u003eForm: capsules\u003c\/li\u003e\n\u003cli\u003ePack size: 60 capsules\u003c\/li\u003e\n\u003cli\u003eStated strength: 10 mg per capsule (manufacturer's label claim)\u003c\/li\u003e\n\u003cli\u003eStated total per pack: 600 mg\u003c\/li\u003e\n\u003cli\u003eIntended use: laboratory research only, not for human consumption\u003c\/li\u003e\n\u003cli\u003eSold to adults aged 18 and over\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eThe strength is the manufacturer's label claim; only a batch certificate confirms it. Because a figure is printed, this pack can be set against other brands of MK-677 on total milligrams, as explained in \u003ca href=\"\/blogs\/news\/price-per-mg-compare-sarms-peptides\"\u003eprice per milligram\u003c\/a\u003e, provided each figure refers to the same form: free base or the heavier mesylate salt.\u003c\/p\u003e\u003ch2\u003eMK-677 in the UK: buying, legal status and what to check\u003c\/h2\u003e\u003cp\u003eUK searches for this compound ask three things: is it legal (\"MK 677 UK legal\"), where can it be bought (\"MK677 UK supplier\", \"MK 677 UK buy\") and can a seller be trusted (\"MK677 UK review\").\u003c\/p\u003e\u003ch3\u003eThe legal position\u003c\/h3\u003e\u003cp\u003eMK-677 is not a licensed medicine in the UK: it has no MHRA marketing authorisation, is not an authorised food supplement, and cannot lawfully be sold for human consumption. It is not a controlled drug either, which is why the question gets contradictory answers online; the restriction concerns what it may be sold as. Free Muscle supplies it to adults aged 18 or over for laboratory research only. It is prohibited at all times under section S2 (peptide hormones, growth factors and related substances) of the WADA Prohibited List. Buyers are responsible for the rules that apply to them, including any anti-doping code. See \u003ca href=\"\/pages\/mk-677-legal-status-uk\"\u003eMK-677 legal status in the UK\u003c\/a\u003e for more detail.\u003c\/p\u003e\u003ch3\u003eWhat a careful UK listing shows, and how this one compares\u003c\/h3\u003e\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eCheck\u003c\/th\u003e\n\u003cth\u003eWhy it matters\u003c\/th\u003e\n\u003cth\u003eThis listing\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eNamed manufacturer and a UK seller\u003c\/td\u003e\n\u003ctd\u003eSomeone is answerable for contents and sale\u003c\/td\u003e\n\u003ctd\u003eMade by iMuscle; sold by FreeMuscle LTD, Scunthorpe\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eStated strength and count\u003c\/td\u003e\n\u003ctd\u003eWithout both there is no pack total to compare\u003c\/td\u003e\n\u003ctd\u003e10 mg x 60 capsules = 600 mg (label claim)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLot number and a certificate for that lot\u003c\/td\u003e\n\u003ctd\u003eA certificate proves nothing unless the numbers match\u003c\/td\u003e\n\u003ctd\u003eiMuscle COA shown only where the manufacturer supplies one for the batch we hold\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eResearch-use terms\u003c\/td\u003e\n\u003ctd\u003eDirections for use mean a product is being sold for consumption\u003c\/td\u003e\n\u003ctd\u003e18+ only; no quantities, timings or promised outcomes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTracked, discreet delivery\u003c\/td\u003e\n\u003ctd\u003eA traceable parcel is a record of the sale\u003c\/td\u003e\n\u003ctd\u003eFree tracked UK delivery in plain packaging; orders before 2pm Monday to Friday processed the same working day; EU 3-7 working days\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWritten returns policy\u003c\/td\u003e\n\u003ctd\u003eTerms are known before payment\u003c\/td\u003e\n\u003ctd\u003e30-day returns on unopened items\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003cp\u003eThe certificate row varies for a third-party brand, so ask us before ordering if a current iMuscle certificate matters to your work. Forum and review searches meet a different limit: user reports describe sellers and parcels, but what a lot contains is a laboratory question. Prices change and appear on the listing, not in this text; cost per milligram is the fair measure. Our \u003ca href=\"\/blogs\/news\/how-to-choose-a-sarms-supplier-uk-checklist\"\u003eUK supplier checklist\u003c\/a\u003e applies the same tests to any shop.\u003c\/p\u003e\u003ch2\u003eCapsules compared with other forms\u003c\/h2\u003e\u003cp\u003eMK-677 is also sold as tablets and research liquids, and is sometimes called a \"peptide\", which it is not. Every MK-677 trial cited here gave it by mouth, as the molecule was designed to be absorbed from the gut; none used an injectable form. Swallowed peptides, by contrast, are largely broken down by digestive enzymes (see \u003ca href=\"\/blogs\/news\/do-oral-peptides-work\"\u003edo oral peptides work\u003c\/a\u003e), which is why the human ipamorelin study below used an intravenous infusion.\u003c\/p\u003e\u003cp\u003eAmong solid forms, the question is how closely each unit matches the label. A capsule's content is fixed when powder, usually blended with a filler, is filled into shells, so an uneven blend lets one capsule differ from the next while the pack average stays right. Licensed medicines are tested for this as content uniformity, unit by unit; a research certificate reporting one pooled figure shows only the average. Tablets fix their content the same way at pressing.\u003c\/p\u003e\u003cp\u003eLiquids carry a concentration instead, so the amount in a measured volume depends on complete dissolution, on the measuring device and on solvent not evaporating after opening, and most compounds degrade faster in solution than dry. None of this implies that one form acts differently in the body; it concerns only what a label and a certificate can vouch for.\u003c\/p\u003e\u003ch2\u003eMK-677 compared with ipamorelin\u003c\/h2\u003e\u003cp\u003e\"Ibutamoren vs ipamorelin\" is the comparison most often searched for this compound. Both are GHS-R1a agonists that prompt the pituitary to release its own growth hormone; the human data show where they part.\u003c\/p\u003e\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003ePoint\u003c\/th\u003e\n\u003cth\u003eMK-677 (this product)\u003c\/th\u003e\n\u003cth\u003eIpamorelin\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eChemical type\u003c\/td\u003e\n\u003ctd\u003eNon-peptide small molecule, C27H36N4O5S, 528.7, CAS 159634-47-6\u003c\/td\u003e\n\u003ctd\u003ePentapeptide Aib-His-D-2-Nal-D-Phe-Lys-NH2, C38H49N9O5, 711.9, CAS 170851-70-4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRoute in human studies\u003c\/td\u003e\n\u003ctd\u003eBy mouth\u003c\/td\u003e\n\u003ctd\u003eIntravenous infusion\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTime course in people\u003c\/td\u003e\n\u003ctd\u003e24-hour growth hormone and IGF-1 raised during weeks of daily use\u003c\/td\u003e\n\u003ctd\u003eOne burst of growth hormone peaking at about 40 minutes; terminal half-life about two hours\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eHuman research base\u003c\/td\u003e\n\u003ctd\u003eRandomised trials in older adults (up to two years) and obese men\u003c\/td\u003e\n\u003ctd\u003eA pharmacokinetic study in healthy men across five infusion rates\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eUK status\u003c\/td\u003e\n\u003ctd\u003eUnlicensed; research use only\u003c\/td\u003e\n\u003ctd\u003eUnlicensed; research use only\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWADA\u003c\/td\u003e\n\u003ctd\u003eS2, prohibited at all times\u003c\/td\u003e\n\u003ctd\u003eS2, prohibited at all times\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003cp\u003eThe time course is the sharpest contrast. In the study by Gobburu and colleagues, healthy men received ipamorelin as a 15-minute intravenous infusion; growth hormone rose in a single episode peaking at around 40 minutes and then declined, and the peptide's terminal half-life was about two hours (Gobburu et al., 1999). The MK-677 trials instead recorded raised 24-hour growth hormone and sustained IGF-1 during daily oral use. Different designs, routes and populations mean these profiles cannot rank the two, and we know of no trial giving both to the same people.\u003c\/p\u003e\u003cp\u003eA PubMed search returns no human study of ipamorelin taken by mouth, so its human pharmacology comes from infusion alone, whereas MK-677's comes from oral use. Our ipamorelin listing is on the \u003ca href=\"\/collections\/ipamorelin\"\u003eipamorelin collection page\u003c\/a\u003e; see also the \u003ca href=\"\/blogs\/news\/ipamorelin-research-guide\"\u003eipamorelin research guide\u003c\/a\u003e and \u003ca href=\"\/blogs\/news\/mk-677-vs-ipamorelin-vs-hgh\"\u003eMK-677 vs ipamorelin vs HGH\u003c\/a\u003e. None of this recommends either compound.\u003c\/p\u003e\u003ch2\u003eReading the certificate of analysis for this product\u003c\/h2\u003e\u003cp\u003eiMuscle is a third-party brand, so any certificate of analysis (COA) for this product is the manufacturer's, not ours. A COA is shown only where iMuscle supplies one for the batch we hold; a generic document is not a substitute for a batch certificate. A real batch certificate carries the lot number printed on the pack, the test method (HPLC or LC-MS) and a purity figure. Free Muscle-brand compounds are assayed batch by batch at Janoshik Analytical; that programme does not cover iMuscle. Read an iMuscle certificate against this page:\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eIdentity.\u003c\/strong\u003e HPLC matches the sample's retention time to an ibutamoren reference standard; LC-MS adds a measured mass, about m\/z 529.25 for protonated C27H36N4O5S.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePurity, as a percentage.\u003c\/strong\u003e It grades the material, not the amount; a high figure is compatible with capsules holding well over or under 10 mg.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eContent per capsule.\u003c\/strong\u003e The line that tests the 10 mg claim; multiplied by 60, it gives the real pack total to set against 600 mg. It should say whether it is expressed as free base or mesylate.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBatch number and test date.\u003c\/strong\u003e These tie the result to your pot and show its age.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eFor this brand, a missing certificate leaves 10 mg and 600 mg as iMuscle's claim only; purity without content supports identity but not strength; a batch number that differs from your pot means another production run. In each case \u003ca href=\"\/pages\/contact\"\u003econtact us\u003c\/a\u003e with the lot number. See \u003ca href=\"\/blogs\/news\/how-to-read-a-certificate-of-analysis\"\u003ehow to read a COA\u003c\/a\u003e and our \u003ca href=\"\/pages\/lab-tests\"\u003elab tests\u003c\/a\u003e page.\u003c\/p\u003e\u003ch2\u003eDetection, sport and testing\u003c\/h2\u003e\u003cp\u003eIbutamoren is prohibited in and out of competition under section S2 of the WADA Prohibited List, named among the growth hormone secretagogues; in the UK the list is applied by UK Anti-Doping. Accredited laboratories screen urine for it and its metabolites, athletes have been sanctioned after positive findings, and strict liability makes an athlete responsible for whatever is in their sample. A research-use label on a product changes nothing in that respect.\u003c\/p\u003e\u003cp\u003eA PubMed search for ibutamoren in urine returns metabolism work in horses and hormone studies in volunteers, but no human excretion study that sets a detection window, so the accurate answer is: detectable, window not established. Windows quoted online without a study behind them deserve no weight, and blood half-life is no guide, because laboratories also target metabolites. Anyone bound by an anti-doping code should treat any exposure to MK-677 as a likely adverse finding and check the current list, which WADA revises every year.\u003c\/p\u003e\u003ch2\u003eStorage, stability and handling\u003c\/h2\u003e\u003cp\u003eWe found no published stability study of ibutamoren capsules, so no shelf life is given here. Any date iMuscle prints on the pack is the limit, and a certificate describes the batch only as it was when tested.\u003c\/p\u003e\u003col\u003e\n\u003cli\u003e\n\u003cstrong\u003eOn arrival.\u003c\/strong\u003e Check the seal and record the lot number and date of receipt; only unopened items can be returned within 30 days. On first opening, count the capsules and tell us the lot number if there are not 60.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIn storage.\u003c\/strong\u003e Keep the pack closed in its original container, cool, dry and away from light. Humidity softens, sticks or cracks capsule shells and speeds the breakdown of damp powder; leave any desiccant sachet in place.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIn use.\u003c\/strong\u003e Wear nitrile gloves, work away from food and drink, and never decant capsules or mix lots, because the lot number on the pack is the only link to its certificate.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThroughout.\u003c\/strong\u003e Keep the product out of reach of children and pets, set aside discoloured, clumped or split capsules, and dispose of surplus as chemical waste, not in household bins or drains.\u003c\/li\u003e\n\u003c\/ol\u003e\u003ch2\u003eGlossary\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eGhrelin mimetic\u003c\/strong\u003e: a compound that activates the ghrelin receptor as the stomach hormone ghrelin itself does.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGHS-R1a\u003c\/strong\u003e: the type 1a growth hormone secretagogue receptor; both compounds compared on this page are agonists at it.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePulse amplitude\u003c\/strong\u003e: the height of each burst of growth hormone; MK-677 raised it without adding bursts.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIGF-1 and IGFBP-3\u003c\/strong\u003e: insulin-like growth factor 1, produced largely by the liver when growth hormone rises, and the protein that carries most of it in blood.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOral glucose tolerance test\u003c\/strong\u003e: a measure of how blood glucose responds to a standard glucose drink; it can reveal impairment while fasting glucose looks normal.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFat-free mass\u003c\/strong\u003e: everything in the body that is not fat, bone and body water included, so it is not a measure of muscle alone.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTerminal half-life\u003c\/strong\u003e: the time for blood concentration to halve once a compound has distributed; about two hours for infused ipamorelin.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eContent uniformity\u003c\/strong\u003e: how closely individual units match the label claim, as opposed to the batch average.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRetention time\u003c\/strong\u003e: how long a compound takes to pass through an HPLC column, the basis of an HPLC identity match.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMesylate\u003c\/strong\u003e: a methanesulfonate salt; ibutamoren mesylate is heavier than the free base, so equal milligrams hold unequal amounts of ibutamoren.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eRelated\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e\n\u003ca href=\"\/collections\/mk-677\"\u003eAll brands of MK-677 (Ibutamoren)\u003c\/a\u003e, compared on strength, pack size and batch testing\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/collections\/brand-imuscle\"\u003eAll iMuscle products\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"\/collections\/mk-677-ibutamoren\"\u003eFree Muscle's own MK-677\u003c\/a\u003e: 10mg, 12.5mg and 25mg, each batch assayed by Janoshik Analytical\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"\/collections\/ipamorelin\"\u003eIpamorelin\u003c\/a\u003e, the peptide compared above\u003c\/li\u003e\n\u003cli\u003eBackground reading: \u003ca href=\"\/blogs\/news\/mk-677-ibutamoren-what-the-research-says\"\u003ethe MK-677 research review\u003c\/a\u003e and \u003ca href=\"\/blogs\/news\/mk-677-brands-compared\"\u003ehow MK-677 brands differ\u003c\/a\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"\/pages\/shipping\"\u003eDelivery\u003c\/a\u003e and \u003ca href=\"\/pages\/guarantee\"\u003ereturns\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cem\u003eThis product is supplied for laboratory research use only. It is not a medicine or a food supplement, has not been evaluated by the MHRA, EMA or FDA, and is not for human consumption. Sold to adults aged 18 and over. Nothing on this page is medical, dosing or usage advice.\u003c\/em\u003e\u003c\/p\u003e\u003ch2\u003eReferences\u003c\/h2\u003e\u003col\u003e\n\u003cli\u003eChapman IM, et al. Stimulation of the growth hormone (GH)-insulin-like growth factor I axis by daily oral administration of a GH secretogogue (MK-677) in healthy elderly subjects. J Clin Endocrinol Metab. 1996;81(12):4249-57. PMID: 8954023.\u003c\/li\u003e\n\u003cli\u003eSvensson J, et al. Two-month treatment of obese subjects with the oral growth hormone (GH) secretagogue MK-677 increases GH secretion, fat-free mass, and energy expenditure. J Clin Endocrinol Metab. 1998;83(2):362-9. PMID: 9467542.\u003c\/li\u003e\n\u003cli\u003eNass R, et al. Effects of an oral ghrelin mimetic on body composition and clinical outcomes in healthy older adults: a randomized trial. Ann Intern Med. 2008;149(9):601-11. PMID: 18981485.\u003c\/li\u003e\n\u003cli\u003eGobburu JV, et al. Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers. Pharm Res. 1999;16(9):1412-6. PMID: 10496658.\u003c\/li\u003e\n\u003c\/ol\u003e","brand":"iMuscle","offers":[{"title":"Default Title","offer_id":48468979155170,"sku":null,"price":62.99,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0772\/3499\/5426\/files\/IBUTAMOREN_720x_2aaedf4d-7fbf-48ff-bed3-22513d927b2c.jpg?v=1789931405"},{"product_id":"thoroughbred-labs-mk677","title":"Thoroughbred Labs MK-677","description":"\u003cp\u003eThoroughbred Labs MK-677 is a 60-capsule pack of ibutamoren (MK-677), a ghrelin receptor agonist and growth hormone secretagogue, made by Thoroughbred Labs and stocked by Free Muscle in the \u003ca href=\"\/pages\/muscle-market\"\u003eMuscle Market\u003c\/a\u003e range. The manufacturer prints no per-capsule strength on the label, so we list it as not stated rather than guess. It is sold only for laboratory research, to adults aged 18 and over.\u003c\/p\u003e\u003ch2\u003eAbout MK-677\u003c\/h2\u003e\u003cp\u003eIbutamoren (MK-677, L-163,191, sometimes sold under the name Nutrobal) is a small-molecule, non-peptide agonist of the growth hormone secretagogue receptor, GHS-R1a, the receptor for the hunger hormone ghrelin. Because it is orally available and mimics ghrelin at the pituitary, it stimulates the release of the body's own growth hormone rather than supplying the hormone directly. PubChem records the free base under CAS number 159634-47-6, with formula C27H36N4O5S, molecular weight 528.7 and InChIKey UMUPQWIGCOZEOY-JOCHJYFZSA-N.\u003c\/p\u003e\u003cp\u003eMerck studied MK-677 in the 1990s and 2000s. Chapman and colleagues gave it by mouth once a day to 32 healthy volunteers aged 64 to 81, over study periods of two and four weeks. Growth hormone pulses grew taller without becoming more frequent, and serum IGF-1 climbed into the range seen in young adults; fasting glucose also rose, prolactin went up by 23 per cent while staying within the normal range, and cortisol did not change (Chapman et al., 1996).\u003c\/p\u003e\u003cp\u003eThe longest trial randomised 65 healthy adults aged 60 to 81 to MK-677 or placebo for up to two years, with its main end points assessed at one year (Nass et al., 2008). Fat-free mass rose by an average of 1.1 kg on MK-677 and fell by 0.5 kg on placebo, yet strength and function did not improve. On the other side of the ledger, body weight rose by 2.7 kg on MK-677 and 0.8 kg on placebo, fasting glucose climbed by an average of 0.3 mmol\/L, insulin sensitivity fell and cortisol rose. Increased appetite, which eased after a few months, and transient mild leg swelling and muscle pain were the commonest side effects. MK-677 has never been licensed as a medicine. None of this research constitutes a claim about the product on this page.\u003c\/p\u003e\u003ch2\u003eThis listing\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eCompound: MK-677 (Ibutamoren)\u003c\/li\u003e\n\u003cli\u003eBrand: Thoroughbred Labs\u003c\/li\u003e\n\u003cli\u003eForm: capsules\u003c\/li\u003e\n\u003cli\u003ePack size: 60 capsules\u003c\/li\u003e\n\u003cli\u003eStrength per capsule: not stated by the manufacturer on the label\u003c\/li\u003e\n\u003cli\u003eTotal per pack: cannot be calculated without a stated strength\u003c\/li\u003e\n\u003cli\u003eIntended use: laboratory research only, not for human consumption\u003c\/li\u003e\n\u003cli\u003eSold to adults aged 18 and over\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eWith no strength on the label there is no total per pack and no price per milligram, so this pack cannot be set against brands that print a figure. The one document that could supply a measured content is a batch certificate, where Thoroughbred Labs provides one. The method for packs that do state a strength is explained in \u003ca href=\"\/blogs\/news\/price-per-mg-compare-sarms-peptides\"\u003eprice per milligram\u003c\/a\u003e.\u003c\/p\u003e\u003ch2\u003eMK-677 in the UK: buying, legal status and what to check\u003c\/h2\u003e\u003cp\u003eOf the UK searches for this compound, \"MK 677 UK legal\" is a question about the law, while \"MK677 UK buy\" and \"MK677 UK supplier\" come down to what a listing lets you verify.\u003c\/p\u003e\u003ch3\u003eThe legal position\u003c\/h3\u003e\u003cp\u003eIbutamoren has never received an MHRA marketing authorisation, so in the UK it is not a licensed medicine. Nor is it an authorised food supplement, so nobody may lawfully sell it for people to consume. It is not a controlled drug. Free Muscle therefore sells it only as a laboratory research compound, to buyers aged 18 or over. WADA prohibits it at all times under section S2, and each buyer is responsible for the rules that bind them, an anti-doping code included. More detail is on our \u003ca href=\"\/pages\/mk-677-legal-status-uk\"\u003eMK-677 legal status in the UK\u003c\/a\u003e page.\u003c\/p\u003e\u003ch3\u003eWhat a UK listing should let you check\u003c\/h3\u003e\u003col\u003e\n\u003cli\u003e\n\u003cstrong\u003eNamed businesses.\u003c\/strong\u003e Thoroughbred Labs manufactures the capsules; FreeMuscle LTD, a UK company based in Scunthorpe, sells and ships them.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eA strength and a count.\u003c\/strong\u003e The count is 60 capsules; the strength is missing because the manufacturer does not state it.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eA lot number tied to a certificate.\u003c\/strong\u003e We show a certificate only where Thoroughbred Labs supplies one for the batch we hold; email us to ask whether one exists for the current stock.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNo directions for use.\u003c\/strong\u003e A research compound cannot also be sold for consumption, so no quantities or promised outcomes appear here.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eA parcel you can follow.\u003c\/strong\u003e Each UK order goes out free, tracked and in plain packaging, and anything ordered before 2pm on a weekday is processed that working day; EU orders arrive in 3-7 working days.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eA published returns policy.\u003c\/strong\u003e A sealed pack can be sent back within 30 days; our \u003ca href=\"\/pages\/shipping\"\u003edelivery\u003c\/a\u003e and \u003ca href=\"\/pages\/guarantee\"\u003eguarantee\u003c\/a\u003e pages give the conditions.\u003c\/li\u003e\n\u003c\/ol\u003e\u003cp\u003eAgainst that list, this pack's weak point is the missing strength. Where a stated figure matters, the \u003ca href=\"\/collections\/mk-677\"\u003eMK-677 collection\u003c\/a\u003e includes packs that print one, such as iMuscle's \u003ca href=\"\/products\/imuscle-ibutamoren-mk-677-60-10mg\"\u003e10mg capsules\u003c\/a\u003e and Free Muscle's own \u003ca href=\"\/products\/mk-677-ibutamoren-10mg\"\u003e10mg\u003c\/a\u003e, \u003ca href=\"\/products\/mk-677-ibutamoren-12-5mg\"\u003e12.5mg\u003c\/a\u003e and \u003ca href=\"\/products\/mk-677-ibutamoren-25mg\"\u003e25mg\u003c\/a\u003e strengths, which Janoshik Analytical assays batch by batch. Forum threads and reviews can report how a parcel arrived, never what a capsule held. Our \u003ca href=\"\/blogs\/news\/how-to-choose-a-sarms-supplier-uk-checklist\"\u003eUK supplier checklist\u003c\/a\u003e applies the same tests to any shop.\u003c\/p\u003e\u003ch2\u003eCapsules compared with other forms\u003c\/h2\u003e\u003cp\u003eMK-677 is searched for as tablets, capsules, liquid and even as a \"peptide\". It is not a peptide but a synthetic small molecule designed to mimic growth hormone releasing peptides at their receptor while staying active by mouth; both trials above gave it orally, and neither used an injectable form. The digestive breakdown that limits swallowed peptides (see \u003ca href=\"\/blogs\/news\/do-oral-peptides-work\"\u003edo oral peptides work\u003c\/a\u003e) is therefore not the issue. What changes between forms is where the stated amount can drift and what a certificate can vouch for.\u003c\/p\u003e\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eForm\u003c\/th\u003e\n\u003cth\u003eWhere the stated amount can drift\u003c\/th\u003e\n\u003cth\u003eWhat to ask of its certificate\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eCapsules (this product)\u003c\/td\u003e\n\u003ctd\u003eUneven blending or fill weight between capsules\u003c\/td\u003e\n\u003ctd\u003eDoes it report milligrams found per capsule, not only purity?\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTablets\u003c\/td\u003e\n\u003ctd\u003eBlend uniformity, and uneven halves if a tablet is split\u003c\/td\u003e\n\u003ctd\u003eIs content per tablet measured on the finished tablets?\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLiquids\u003c\/td\u003e\n\u003ctd\u003eSettling or crystallising, solvent loss from an opened bottle, dropper error\u003c\/td\u003e\n\u003ctd\u003eWas the finished liquid tested, and when? A raw-powder certificate says nothing about concentration.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLoose powder\u003c\/td\u003e\n\u003ctd\u003eEvery portion depends on the accuracy of a balance at milligram scale\u003c\/td\u003e\n\u003ctd\u003eIdentity and purity are all it can confirm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003cp\u003eSalt form matters too. Ibutamoren is often made as its mesylate (methanesulfonate) salt, which is heavier than the free base, so a milligram of salt holds less than a milligram of ibutamoren; a label or certificate should say which it means. None of this suggests one form performs differently; it concerns only what can be verified.\u003c\/p\u003e\u003ch2\u003eMK-677 compared with ipamorelin\u003c\/h2\u003e\u003cp\u003e\"Ibutamoren vs ipamorelin\" is the comparison most searched for this compound. Both activate GHS-R1a and prompt the pituitary to release its own growth hormone, but they are different kinds of molecule with unequal research records.\u003c\/p\u003e\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eFeature\u003c\/th\u003e\n\u003cth\u003eMK-677 (this product)\u003c\/th\u003e\n\u003cth\u003eIpamorelin\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eType of molecule\u003c\/td\u003e\n\u003ctd\u003eNon-peptide small molecule\u003c\/td\u003e\n\u003ctd\u003ePentapeptide, Aib-His-D-2-Nal-D-Phe-Lys-NH2\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFormula and molecular weight\u003c\/td\u003e\n\u003ctd\u003eC27H36N4O5S, 528.7\u003c\/td\u003e\n\u003ctd\u003eC38H49N9O5, 711.9\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMain published evidence\u003c\/td\u003e\n\u003ctd\u003eRandomised placebo-controlled trials in older adults, the longest two years\u003c\/td\u003e\n\u003ctd\u003eRat and pig pharmacology; a small human literature\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCortisol\u003c\/td\u003e\n\u003ctd\u003eUnchanged over four weeks (1996); raised at twelve months (2008)\u003c\/td\u003e\n\u003ctd\u003eNot raised in pigs beyond the level seen with GHRH\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLicensed as a medicine\u003c\/td\u003e\n\u003ctd\u003eNowhere\u003c\/td\u003e\n\u003ctd\u003eNowhere\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWADA\u003c\/td\u003e\n\u003ctd\u003eS2, prohibited at all times\u003c\/td\u003e\n\u003ctd\u003eS2, prohibited at all times\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003cp\u003eThe word that separates them is \"selective\". In the 1998 paper introducing ipamorelin, Novo Nordisk researchers found that in conscious pigs it released growth hormone about as potently as the older peptide GHRP-6 but, unlike GHRP-6 and GHRP-2, did not raise ACTH or cortisol above the levels seen with GHRH, even at amounts far beyond those needed for a growth hormone response (Raun et al., 1998). For MK-677 the comparable data are human: cortisol held steady over four weeks but rose over twelve months. Species, designs and durations differ, so these results cannot show which is more selective in people, and we know of no trial giving both to the same participants.\u003c\/p\u003e\u003cp\u003eIpamorelin is a peptide, so absorption by mouth is an open question for it in a way it is not for MK-677; its human studies are summarised in the \u003ca href=\"\/blogs\/news\/ipamorelin-research-guide\"\u003eipamorelin research guide\u003c\/a\u003e. Regulatory status is identical: both are unlicensed, sold here only for laboratory research to adults, and listed in WADA section S2. The ipamorelin we stock is on the \u003ca href=\"\/collections\/ipamorelin\"\u003eipamorelin collection page\u003c\/a\u003e, and \u003ca href=\"\/blogs\/news\/mk-677-vs-ipamorelin-vs-hgh\"\u003eMK-677 vs ipamorelin vs HGH\u003c\/a\u003e adds somatropin to the comparison. None of this recommends either compound.\u003c\/p\u003e\u003ch2\u003eReading the certificate of analysis for this product\u003c\/h2\u003e\u003cp\u003eThoroughbred Labs, not Free Muscle, is the source of any certificate of analysis (COA) for this product. For third-party brands we display a COA only when the manufacturer has supplied one for the batch actually in our stock, and otherwise say none is available rather than show a generic document; email us before ordering to ask what exists for the current batch. Janoshik Analytical's independent batch testing covers Free Muscle-brand compounds only, not Thoroughbred Labs stock. Where a certificate exists, read it field by field.\u003c\/p\u003e\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eField\u003c\/th\u003e\n\u003cth\u003eWhat it should show for this product\u003c\/th\u003e\n\u003cth\u003eIf it is missing\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eCompound\u003c\/td\u003e\n\u003ctd\u003eIbutamoren or MK-677, ideally with CAS 159634-47-6\u003c\/td\u003e\n\u003ctd\u003eThe document may describe another product\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eIdentity method\u003c\/td\u003e\n\u003ctd\u003eRetention time matched to an ibutamoren reference standard by HPLC, or an LC-MS mass that fits C27H36N4O5S\u003c\/td\u003e\n\u003ctd\u003eA purity figure alone does not prove the substance is ibutamoren\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eStereochemistry\u003c\/td\u003e\n\u003ctd\u003eThe (2R) form in PubChem's systematic name and InChIKey\u003c\/td\u003e\n\u003ctd\u003eIts enantiomer weighs exactly the same, so only a chiral separation can exclude it; without one the question stays open\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePurity\u003c\/td\u003e\n\u003ctd\u003eA percentage, usually from HPLC peak areas\u003c\/td\u003e\n\u003ctd\u003eImpurities and breakdown products are unknown\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eContent per capsule\u003c\/td\u003e\n\u003ctd\u003eMilligrams found per capsule, stating whether as free base or mesylate\u003c\/td\u003e\n\u003ctd\u003eThe pack's total content stays unknown, since the label gives no strength\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBatch number\u003c\/td\u003e\n\u003ctd\u003eThe same lot as printed on your pack\u003c\/td\u003e\n\u003ctd\u003eIt describes other stock\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTest date and laboratory\u003c\/td\u003e\n\u003ctd\u003eA date and a named laboratory that can confirm the report\u003c\/td\u003e\n\u003ctd\u003eThe result cannot be traced or dated\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003cp\u003eFor this pack the content row matters most: purity without milligrams per capsule confirms the substance but not the amount. See \u003ca href=\"\/blogs\/news\/how-to-read-a-certificate-of-analysis\"\u003ehow to read a COA\u003c\/a\u003e and our \u003ca href=\"\/pages\/lab-tests\"\u003elab tests\u003c\/a\u003e page, and \u003ca href=\"\/pages\/contact\"\u003econtact us\u003c\/a\u003e with the lot number if a certificate does not match your pack.\u003c\/p\u003e\u003ch2\u003eDetection, sport and testing\u003c\/h2\u003e\u003cp\u003eWADA names ibutamoren among the growth hormone secretagogues in section S2 of the Prohibited List, banned in and out of competition. Accredited laboratories screen urine for it and its metabolites, and under strict liability an athlete answers for whatever is found in their sample, however it got there.\u003c\/p\u003e\u003cp\u003eHow long it stays detectable is less settled. We have found no verified human study that sets a urine detection window. Hair has been studied: in a forensic report, hair collected four weeks after a single oral exposure in one male volunteer tested positive for ibutamoren, using a method with a limit of detection of 0.1 pg\/mg (Kintz and Gheddar, 2026). The authors wanted reference data because anti-doping authorities have urged caution over hair results in Court of Arbitration for Sport hearings. One volunteer and one exposure cannot define a window, and the finding concerns hair rather than the urine samples most tests rely on. For urine the accurate statement is: detectable, window not established. Anyone bound by an anti-doping code should treat any contact with MK-677 as a risk of an adverse finding.\u003c\/p\u003e\u003ch2\u003eStorage, stability and handling\u003c\/h2\u003e\u003cp\u003eTo our knowledge nobody has published a stability study of ibutamoren in capsule form, so no shelf life is quoted here. Work to any date Thoroughbred Labs prints on the pack; a certificate describes a batch only as it was when tested.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eOriginal container.\u003c\/strong\u003e The lot number on the manufacturer's pack is what ties the capsules to a certificate. Decanting them breaks that link, and so does mixing capsules from two packs.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCool, dry and dark.\u003c\/strong\u003e Keep the pack away from radiators, sunny windowsills and steamy rooms, as capsule shells absorb moisture and can soften and stick together.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSealed.\u003c\/strong\u003e Close the lid fully after each opening, leaving any desiccant sachet in place.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eChecked.\u003c\/strong\u003e Set aside discoloured, clumped or cracked capsules and report the lot number to us.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRecorded and handled with care.\u003c\/strong\u003e Log the dates of receipt and first opening, wear nitrile gloves, keep the material away from food and out of reach of children and pets, and send surplus for chemical waste disposal.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eKeep the seal intact until needed, because the 30-day return option covers unopened items only.\u003c\/p\u003e\u003ch2\u003eGlossary\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eIbutamoren\u003c\/strong\u003e: the International Nonproprietary Name for MK-677, whose Merck codes include L-163,191 and MK-0677.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGrowth hormone secretagogue\u003c\/strong\u003e: the class name for compounds, ibutamoren among them, that raise growth hormone by acting on the pituitary instead of replacing the hormone.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGHS-R1a\u003c\/strong\u003e: growth hormone secretagogue receptor type 1a, the receptor ghrelin binds and the one both MK-677 and ipamorelin activate.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIGF-1\u003c\/strong\u003e: insulin-like growth factor 1, made largely in the liver in response to growth hormone; trials use its level as a sign that the growth hormone axis has been stimulated.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFat-free mass\u003c\/strong\u003e: everything except fat, including water and organs, so a rise is not the same as a muscle gain.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInsulin sensitivity\u003c\/strong\u003e: how strongly tissues respond to insulin; when it falls, blood glucose tends to rise, as in the MK-677 trials.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFree base and mesylate\u003c\/strong\u003e: the neutral molecule and its heavier methanesulfonate salt; milligram figures for one do not transfer to the other.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEnantiomer\u003c\/strong\u003e: either of two mirror-image versions of one molecule, identical in mass and separable only by chiral analysis.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLimit of detection\u003c\/strong\u003e: the lowest concentration at which a test can confirm a substance is present.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eRelated\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e\n\u003ca href=\"\/collections\/mk-677\"\u003eEvery MK-677 brand we stock\u003c\/a\u003e, side by side on strength and batch testing\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/collections\/brand-thoroughbred-labs\"\u003eThe Thoroughbred Labs range\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003eRelated collections: \u003ca href=\"\/collections\/ipamorelin\"\u003eIpamorelin\u003c\/a\u003e, \u003ca href=\"\/collections\/mk-777\"\u003eMK-777 (Acetamoren)\u003c\/a\u003e and \u003ca href=\"\/collections\/hgh\"\u003eHGH (Somatropin)\u003c\/a\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"\/blogs\/news\/mk-677-ibutamoren-what-the-research-says\"\u003eMK-677 (ibutamoren): what the research says\u003c\/a\u003e and \u003ca href=\"\/blogs\/news\/mk-677-brands-compared\"\u003eMK-677 by brand\u003c\/a\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"\/pages\/shipping\"\u003eDelivery\u003c\/a\u003e and \u003ca href=\"\/pages\/guarantee\"\u003ereturns\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cem\u003eResearch use only: Thoroughbred Labs MK-677 is neither a medicine nor a food supplement, has not been evaluated by the MHRA, EMA or FDA, and is not for human consumption. We sell it only to adults aged 18 and over, and nothing on this page is medical, dosing or usage advice.\u003c\/em\u003e\u003c\/p\u003e\u003ch2\u003eReferences\u003c\/h2\u003e\u003col\u003e\n\u003cli\u003eChapman IM, et al. Stimulation of the growth hormone (GH)-insulin-like growth factor I axis by daily oral administration of a GH secretogogue (MK-677) in healthy elderly subjects. J Clin Endocrinol Metab. 1996;81(12):4249-57. PMID: 8954023.\u003c\/li\u003e\n\u003cli\u003eNass R, et al. Effects of an oral ghrelin mimetic on body composition and clinical outcomes in healthy older adults: a randomized trial. Ann Intern Med. 2008;149(9):601-11. PMID: 18981485.\u003c\/li\u003e\n\u003cli\u003eRaun K, et al. Ipamorelin, the first selective growth hormone secretagogue. Eur J Endocrinol. 1998;139(5):552-61. PMID: 9849822.\u003c\/li\u003e\n\u003cli\u003eKintz P, Gheddar L. Knowing the minimal detectable dose can facilitate the interpretation of a hair test result: II. Case example with ibutamoren (MK-677), a growth hormone secretagogue. Clin Chim Acta. 2026;578:120578. PMID: 40882886.\u003c\/li\u003e\n\u003c\/ol\u003e","brand":"Thoroughbred Labs","offers":[{"title":"Default Title","offer_id":48468980531426,"sku":null,"price":44.99,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0772\/3499\/5426\/files\/MK_9dbb4d7d-429d-47d4-a596-5b0cd5958d9f.png?v=1789931427"},{"product_id":"yakka-strength-yakka-strength-mk677","title":"Yakka Strength MK-677","description":"\u003cp\u003eYakka Strength MK-677 is a pack of 60 capsules of ibutamoren, the orally active growth hormone secretagogue better known by its development code MK-677. Yakka Strength manufactures it, and Free Muscle stocks it in the \u003ca href=\"\/pages\/muscle-market\"\u003eMuscle Market\u003c\/a\u003e range for laboratory research by adults aged 18 and over. No per-capsule strength is given in the product information we hold for this listing, so none is quoted here.\u003c\/p\u003e\n\u003ch2\u003eAbout MK-677\u003c\/h2\u003e\n\u003cp\u003eIbutamoren is also sold as MK-677, MK-0677, L-163,191, ibutamoren mesylate (its salt form) and Nutrobal. Merck designed it in the 1990s as a non-peptide molecule that reproduces the action of the growth hormone releasing peptides while remaining active when swallowed. It is not a SARM and does not target the androgen receptor. It activates the ghrelin receptor, GHS-R1a, which signals the pituitary to release growth hormone in pulses; the liver answers with more insulin-like growth factor 1 (IGF-1).\u003c\/p\u003e\n\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eIdentifier\u003c\/th\u003e\n\u003cth\u003eIbutamoren (free base)\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eCAS number\u003c\/td\u003e\n\u003ctd\u003e159634-47-6\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMolecular formula\u003c\/td\u003e\n\u003ctd\u003eC27H36N4O5S\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMolecular weight\u003c\/td\u003e\n\u003ctd\u003e528.7 g\/mol\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInChIKey\u003c\/td\u003e\n\u003ctd\u003eUMUPQWIGCOZEOY-JOCHJYFZSA-N\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePubChem CID\u003c\/td\u003e\n\u003ctd\u003e178024\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp\u003eThese PubChem values describe the free base. The 2011 trial below used ibutamoren mesylate, a salt, and that distinction matters on a certificate.\u003c\/p\u003e\n\u003ch3\u003eWhat the published research reports\u003c\/h3\u003e\n\u003cp\u003eUnusually for a research compound, ibutamoren has a real human trial record. In a 1996 placebo-controlled study, 32 healthy volunteers aged 64 to 81 were assigned to placebo or once-daily oral ibutamoren for two and four weeks. Growth hormone rose because existing pulses grew larger, not more frequent, and at the highest of the three daily amounts tested, IGF-1 reached the range typical of young adults. Fasting glucose and prolactin also rose.\u003c\/p\u003e\n\u003cp\u003eThe longest trial, published in 2008, randomised 65 healthy adults aged 60 to 81. Over the first year, fat-free mass rose by 1.1 kg with ibutamoren and fell by 0.5 kg with placebo, but strength and function did not change, total fat mass and abdominal visceral fat did not differ, and body weight and limb fat rose more than with placebo. Adverse findings included increased appetite, mild transient swelling of the lower legs, muscle pain, a 0.3 mmol\/L rise in fasting glucose, reduced insulin sensitivity and higher cortisol. The authors judged the study too small and short to assess function.\u003c\/p\u003e\n\u003cp\u003eIbutamoren mesylate was also tested in a 2011 phase IIb trial in 123 older people recovering from hip fracture. IGF-1 went up and gait speed improved, while stair-climbing power and several other functional measures did not. Congestive heart failure in a small number of patients led to the trial being halted early, and the investigators concluded that the adverse-effect profile was unfavourable in that group. Merck did not take ibutamoren to approval. These findings describe study participants and are not claims about this product.\u003c\/p\u003e\n\u003ch2\u003eThis listing\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eCompound: MK-677 (Ibutamoren)\u003c\/li\u003e\n\u003cli\u003eBrand and manufacturer: Yakka Strength\u003c\/li\u003e\n\u003cli\u003eForm: capsules\u003c\/li\u003e\n\u003cli\u003ePack size: 60 capsules\u003c\/li\u003e\n\u003cli\u003eStrength per capsule: not stated in the product information we hold\u003c\/li\u003e\n\u003cli\u003eTotal per pack: cannot be calculated without a stated strength\u003c\/li\u003e\n\u003cli\u003eIntended use: laboratory research only, not for human consumption\u003c\/li\u003e\n\u003cli\u003eSold to adults aged 18 and over\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eWith no stated strength, neither milligrams per pack nor cost per milligram can be worked out, so this pack cannot be ranked against brands that print a figure (method: \u003ca href=\"\/blogs\/news\/price-per-mg-compare-sarms-peptides\"\u003eprice per milligram\u003c\/a\u003e). Only a batch certificate can supply a measured content.\u003c\/p\u003e\n\u003ch2\u003eMK-677 in the UK: buying, legal status and what to check\u003c\/h2\u003e\n\u003cp\u003eThree of the commonest UK searches, \"MK 677 UK legal\", \"MK677 UK buy\" and \"MK677 UK supplier\", raise two questions: may it be bought here, and what separates a sound seller from a poor one.\u003c\/p\u003e\n\u003ch3\u003eThe legal position\u003c\/h3\u003e\n\u003cp\u003eUK law does not list ibutamoren as a controlled drug, but being uncontrolled is not the same as being approved. Without an MHRA marketing authorisation it cannot be marketed as a medicine, and as it is neither an authorised food supplement nor an authorised novel food, it cannot be marketed as food. It cannot lawfully be sold for human consumption. That leaves supply as a research compound for laboratory work: the only way Free Muscle lists it, and only to buyers aged 18 or over. In sport it is banned at all times (see detection, below), and buyers are responsible for the rules that apply to them, including any anti-doping code. Detail is on our \u003ca href=\"\/pages\/mk-677-legal-status-uk\"\u003eMK-677 legal status in the UK\u003c\/a\u003e page.\u003c\/p\u003e\n\u003ch3\u003eWhat a trustworthy UK listing shows\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eA lot number printed on the pack\u003c\/strong\u003e, which is what links the contents to any test result.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eA batch-specific certificate of analysis\u003c\/strong\u003e, rather than a generic or undated PDF.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eA stated strength per capsule\u003c\/strong\u003e, ideally saying whether it means free base or mesylate salt.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eA manufacturer's name\u003c\/strong\u003e, plus a UK seller with a registered company and a way to reach it.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eResearch-use terms\u003c\/strong\u003e: 18+ only, no usage directions, no promised outcomes.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTracked delivery in plain packaging\u003c\/strong\u003e and a published returns policy.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eHow this listing measures up\u003c\/h3\u003e\n\u003cp\u003eMeasured against that list, the seller, research-use and delivery points are met outright. FreeMuscle LTD is a UK company in Scunthorpe, the manufacturer is named, and every order goes by free tracked UK delivery in plain packaging. Orders placed before 2pm Monday to Friday are processed the same working day, EU delivery takes 3-7 working days, and unopened items can be returned within 30 days. The certificate point depends on the batch, because a Yakka Strength COA is shown only where the manufacturer supplies one. The strength point is not met: the product information we hold gives no figure. Price searches meet the same limit: prices change and appear on the listing itself, and a fair comparison is price per milligram, which needs a stated strength. More checks are in our \u003ca href=\"\/blogs\/news\/how-to-choose-a-sarms-supplier-uk-checklist\"\u003eUK supplier checklist\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch2\u003eCapsules compared with other forms\u003c\/h2\u003e\n\u003cp\u003eSearches for \"MK 677 tablet\", \"MK677 tablets\" and \"MK677 UK liquid\" show that ibutamoren turns up in several formats: capsules, pressed tablets and so-called research liquids. The active molecule does not change between them; the way each unit's content is fixed, and how well that content holds up, does.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eCapsules\u003c\/strong\u003e contain a set fill of powder, normally mixed with a bulking excipient. How evenly that blend was mixed decides how consistent each capsule is, and the shell keeps the dry powder largely away from air and moisture.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTablets\u003c\/strong\u003e add compression and binders to the same blending step, so their content is likewise fixed when they are made.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLiquids\u003c\/strong\u003e depend on complete and lasting dissolution, and each drawn volume is only as accurate as the pipette used. In solution most compounds degrade faster than when dry, and if solvent evaporates the concentration creeps upward.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eBecause ibutamoren is a small non-peptide molecule, the enzymatic digestion that limits peptides taken by mouth does not apply to it in the same way; it was designed to be orally active, and the 1996 and 2008 trials above gave it by mouth. Peptide secretagogues are in the opposite position (see \u003ca href=\"\/blogs\/news\/do-oral-peptides-work\"\u003edo oral peptides work\u003c\/a\u003e). None of this suggests any format produces an effect. The practical difference is verification: a capsule certificate can report content per capsule, a liquid one reports concentration.\u003c\/p\u003e\n\u003ch2\u003eMK-677 compared with ipamorelin\u003c\/h2\u003e\n\u003cp\u003eOf the related compounds, ipamorelin is the one most often searched against this one (\"ibutamoren vs ipamorelin\"). The two share a receptor, GHS-R1a, and a mode of action: each makes the pituitary release growth hormone it already holds. Almost everything else that can be documented about them differs.\u003c\/p\u003e\n\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003ePoint\u003c\/th\u003e\n\u003cth\u003eMK-677 (ibutamoren)\u003c\/th\u003e\n\u003cth\u003eIpamorelin\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eChemical type\u003c\/td\u003e\n\u003ctd\u003eNon-peptide small molecule\u003c\/td\u003e\n\u003ctd\u003eSynthetic pentapeptide\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFormula\u003c\/td\u003e\n\u003ctd\u003eC27H36N4O5S\u003c\/td\u003e\n\u003ctd\u003eC38H49N9O5\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMolecular weight\u003c\/td\u003e\n\u003ctd\u003e528.7 g\/mol\u003c\/td\u003e\n\u003ctd\u003e711.9 g\/mol\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOrigin\u003c\/td\u003e\n\u003ctd\u003eMerck, 1990s\u003c\/td\u003e\n\u003ctd\u003eNovo Nordisk, described 1998\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eHuman trials\u003c\/td\u003e\n\u003ctd\u003eSeveral randomised trials, up to two years\u003c\/td\u003e\n\u003ctd\u003eFew, none measuring muscle or strength that we know of\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eUK status\u003c\/td\u003e\n\u003ctd\u003eUnlicensed research compound\u003c\/td\u003e\n\u003ctd\u003eUnlicensed research compound\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWADA\u003c\/td\u003e\n\u003ctd\u003eS2.2.4, named\u003c\/td\u003e\n\u003ctd\u003eS2.2.4, named\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp\u003eFirst, route: ibutamoren was built to survive the gut, whereas ipamorelin is a chain of five amino acids of the kind digestive enzymes break down, so oral ipamorelin products have no published clinical evidence behind them that we know of. Second, evidence: ibutamoren's trials measured body composition and recorded adverse effects, from raised glucose to the heart failure signal after hip fracture, while ipamorelin's human literature is thin. Third, status, where they converge: neither is licensed in the UK or a controlled drug, and WADA names both in section S2.2.4 as growth hormone secretagogues, prohibited at all times.\u003c\/p\u003e\n\u003cp\u003eA PubMed search for both names together returns reviews, chemistry and animal work but no head-to-head trial in people, so neither can be called stronger, and we do not rank research compounds by effect. Brands held are in the \u003ca href=\"\/collections\/ipamorelin\"\u003eipamorelin collection\u003c\/a\u003e, both are set against prescription somatropin in \u003ca href=\"\/blogs\/news\/mk-677-vs-ipamorelin-vs-hgh\"\u003eMK-677 vs ipamorelin vs somatropin\u003c\/a\u003e, and the peptide's own studies are summarised in the \u003ca href=\"\/blogs\/news\/ipamorelin-research-guide\"\u003eipamorelin research guide\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch2\u003eReading the certificate of analysis for this product\u003c\/h2\u003e\n\u003cp\u003eYakka Strength manufactures this product, so a certificate of analysis (COA) for it can only come from them. We display one only when they have provided it for the batch in our stock, either linked here or emailed on request; where there is none, we state that plainly instead of posting a generic PDF. Free Muscle's own \u003ca href=\"\/collections\/mk-677-ibutamoren\"\u003eMK-677 capsules\u003c\/a\u003e (10mg, 12.5mg and 25mg) are assayed batch by batch at Janoshik Analytical, an independent laboratory; that does not extend to Yakka Strength. On a Yakka Strength certificate, read:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eIdentity (HPLC or LC-MS).\u003c\/strong\u003e HPLC infers identity from a peak matching a reference standard's retention time. LC-MS measures mass: ibutamoren gives a protonated ion near m\/z 529, whether the sample was free base or mesylate, because the salt partner separates in solution.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePurity (%).\u003c\/strong\u003e An HPLC peak-area share. It grades the material, not the capsule, and gives no milligram figure.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eContent per capsule, and in which form.\u003c\/strong\u003e The line this product needs most. Methanesulfonic acid adds about 96 g\/mol, so free base is roughly 85 per cent of the mesylate salt by mass (528.7 divided by about 624.8); the two figures are not interchangeable.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBatch number.\u003c\/strong\u003e Must match the lot on the pack in hand.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest date and laboratory.\u003c\/strong\u003e Shows the result's age and who can confirm it.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eGaps have plain consequences here. Without identity, nothing confirms the capsules hold ibutamoren; purity with no content line leaves the amount per capsule unknown; a missing or different batch number means the report belongs to another batch. \u003ca href=\"\/pages\/contact\"\u003eContact us\u003c\/a\u003e with the lot number and we will confirm what exists for current stock. See also \u003ca href=\"\/blogs\/news\/how-to-read-a-certificate-of-analysis\"\u003ehow to read a COA\u003c\/a\u003e and our \u003ca href=\"\/pages\/lab-tests\"\u003elab tests\u003c\/a\u003e page.\u003c\/p\u003e\n\u003ch2\u003eDetection, sport and testing\u003c\/h2\u003e\n\u003cp\u003eWADA bans ibutamoren at all times, in and out of competition. Section S2.2.4 (growth hormone releasing factors) names \"ibutamoren (MK-677)\" as an example of a growth hormone secretagogue, and every substance in section S2 is non-Specified. Because it is named on the list, WADA-accredited laboratories test for it, and strict liability applies: an athlete answers for any prohibited substance in their sample, whatever its source.\u003c\/p\u003e\n\u003cp\u003eFor urine, the usual sample, a PubMed search found metabolism studies in horses but no published human excretion study, so the accurate statement is: detectable, window not established. Hair has some human data. In a forensic study from Strasbourg, ibutamoren was measured at 1.3 pg\/mg in a male volunteer's hair collected four weeks after a single exposure (detection limit 0.1 pg\/mg), and at 224 pg\/mg in hair from a person who had taken it repeatedly for sporting purposes. Anyone subject to testing should assume exposure will be found.\u003c\/p\u003e\n\u003ch2\u003eStorage, stability and handling\u003c\/h2\u003e\n\u003cp\u003eKeep the pack closed in its original container somewhere cool, dry and dark, away from radiators, sunny windows and kitchen steam. Humidity is the main threat: shells absorb water and soften or fuse, and damp powder breaks down faster, while hot, very dry air makes shells brittle. If the pack is refrigerated, let it reach room temperature before opening so condensation does not form inside, and leave any desiccant sachet in the tub.\u003c\/p\u003e\n\u003cp\u003eShelf-life data for ibutamoren capsules do not appear in any published literature we could find, so the printed expiry or best-before date, where there is one, sets the limit. Record when the pack was first opened alongside its batch number. Handle it as a laboratory reagent: gloves for opened capsules or loose powder, away from food and drink, out of reach of children and animals, any removed portion labelled with compound, batch and date, and waste disposed of as chemical waste, not in household bins or drains. Never decant capsules into an unlabelled container; the batch number on the original pack is the only link to a certificate.\u003c\/p\u003e\n\u003ch2\u003eGlossary\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eGrowth hormone secretagogue\u003c\/strong\u003e: the drug class ibutamoren belongs to, defined by causing the pituitary to secrete more of its own growth hormone.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGHS-R1a\u003c\/strong\u003e: the receptor through which the stomach hormone ghrelin acts; ibutamoren and ipamorelin both activate it.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIGF-1\u003c\/strong\u003e: insulin-like growth factor 1, a hormone whose blood level tracks growth hormone output, most of it produced by the liver.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePulsatile secretion\u003c\/strong\u003e: the pattern in which growth hormone leaves the pituitary as a series of peaks, not a constant flow.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIbutamoren mesylate\u003c\/strong\u003e: the methanesulfonic acid salt of ibutamoren, heavier than the free base.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFree base\u003c\/strong\u003e: the molecule without a salt partner.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFat-free mass\u003c\/strong\u003e: body mass minus fat, including water, so it rises with fluid retention as well as tissue.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOedema\u003c\/strong\u003e: swelling from fluid collecting in tissues.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInsulin sensitivity\u003c\/strong\u003e: the degree to which muscle, liver and fat respond to insulin; lower sensitivity means glucose is cleared from the blood less readily.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLC-MS\u003c\/strong\u003e: a liquid chromatograph feeding a mass spectrometer, so each separated component is also weighed as ions; the firmer identity test.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003em\/z\u003c\/strong\u003e: mass-to-charge ratio, the value a mass spectrometer reports.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCertificate of analysis (COA)\u003c\/strong\u003e: one batch's laboratory results (identity, purity and content where measured), dated and carrying that batch's number.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eRelated\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003ca href=\"\/collections\/mk-677\"\u003eMK-677 (Ibutamoren) collection\u003c\/a\u003e: all brands held, with strength, pack size and testing set out for each\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"\/collections\/brand-yakka-strength\"\u003eAll Yakka Strength products\u003c\/a\u003e at Free Muscle\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/blogs\/news\/mk-677-ibutamoren-what-the-research-says\"\u003eMK-677 (ibutamoren): what the research says\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"\/pages\/shipping\"\u003eDelivery\u003c\/a\u003e and \u003ca href=\"\/pages\/guarantee\"\u003ereturns\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cem\u003eNot for human consumption. This Yakka Strength pack is supplied for laboratory research use only; it is neither a licensed medicine nor a food supplement, and neither the MHRA nor the EMA or FDA has evaluated it. Orders are restricted to adults aged 18 and over, and nothing on this page amounts to medical, dosing or usage advice.\u003c\/em\u003e\u003c\/p\u003e\n\u003ch2\u003eReferences\u003c\/h2\u003e\n\u003col\u003e\n\u003cli\u003eChapman IM, et al. Stimulation of the growth hormone (GH)-insulin-like growth factor I axis by daily oral administration of a GH secretogogue (MK-677) in healthy elderly subjects. J Clin Endocrinol Metab. 1996;81(12):4249-57. PMID: 8954023.\u003c\/li\u003e\n\u003cli\u003eNass R, et al. Effects of an oral ghrelin mimetic on body composition and clinical outcomes in healthy older adults: a randomized trial. Ann Intern Med. 2008;149(9):601-11. PMID: 18981485.\u003c\/li\u003e\n\u003cli\u003eAdunsky A, et al. MK-0677 (ibutamoren mesylate) for the treatment of patients recovering from hip fracture: a multicenter, randomized, placebo-controlled phase IIb study. Arch Gerontol Geriatr. 2011;53(2):183-9. PMID: 21067829.\u003c\/li\u003e\n\u003cli\u003eKintz P, Gheddar L. Knowing the minimal detectable dose can facilitate the interpretation of a hair test result: II. Case example with ibutamoren (MK-677), a growth hormone secretagogue. Clin Chim Acta. 2026;578:120578. PMID: 40882886.\u003c\/li\u003e\n\u003c\/ol\u003e","brand":"Yakka Strength","offers":[{"title":"Default Title","offer_id":48468982300898,"sku":null,"price":64.99,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0772\/3499\/5426\/files\/yakka-strength-research-capsules-front_600x_6e57c70d-5291-4057-8ead-6a5eefaa09ab.png?v=1789931440"}],"url":"https:\/\/freemuscle.co.uk\/collections\/mk-677.oembed","provider":"Free Muscle","version":"1.0","type":"link"}