IBUTAMOREN
Growth Hormone Secretagogue · 25mg

RESEARCH MK-677 25MG

MK-677 (Ibutamoren) is a growth hormone secretagogue — an agonist at the ghrelin receptor. It is not authorised as a medicine or a food supplement in the UK or EU, and is prohibited in sport by WADA. Supplied for laboratory research use only. 25mg × 60 capsules.

£69.99£84.99-18%
MK-677 Ibutamoren — 25mg · 60 Capsules
25mg IbutamorenGHS-R1a targetCOA per batch60 capsules
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The honest version

WHAT IS
ACTUALLY KNOWN

We would rather you bought with your eyes open than not at all. Here is the state of the evidence, including the parts that do not help us.

01

What it is

This is a growth hormone secretagogue. Ibutamoren is an agonist at the ghrelin (GHS-R1a) receptor.

02

State of the evidence

Has published human trial data, unusually for this category. Development as a medicine was not completed.

03

Known risks

Associated with increased appetite, water retention and raised blood glucose. Not appropriate for anyone with impaired glucose tolerance.

04

Regulatory status

Not authorised as a medicine or a food supplement in the UK or EU.

05

Status in sport

Growth hormone secretagogues are on the WADA Prohibited List and are detectable.

06

What we verify

Identity and purity, per batch, by a laboratory we do not own. We verify what is in the capsule — nothing about what it does.

The breakdown

SPEC SHEET

What is in the bottle, and what is on the certificate.

25mg/ capsule

MK-677 (Ibutamoren)

25mg per capsule, as stated on the certificate of analysis for the batch.

60capsules

Bottle contents

Each bottle contains 60 capsules.

~24hhalf-life

Pharmacokinetics

A long half-life is reported in the published literature. We do not publish a human dosing schedule.

COAper batch

Independently assayed

Each batch is assayed by Janoshik Analytical, an independent laboratory. The Certificate of Analysis for your batch is available on request.

This product is supplied for laboratory research use only. We do not provide dosing instructions, cycle lengths or post-cycle protocols for human use.

-18%MK-677 Ibutamoren — 25mg · 60 Capsules

MK-677 25MG

Growth hormone secretagogue · research use only
£69.99£84.99SAVE £15.00

Tax included · 60 capsules · assayed per batch

Total: £69.99
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Independently assayed per batch
Free, discreet UK delivery
In stock
Verification

WHAT WE CAN
PROVE

We don't have customer reviews to show you yet, and we're not going to invent any. Here is what we can actually put in front of you instead.

Assayed by a lab we don't own

Batches go to Janoshik Analytical, an independent testing laboratory. We don't choose the result.

Tested per batch, not per year

A certificate from a batch made two years ago says nothing about the pack in your hand.

Batch number on the pack

Email it to us with the product name and we'll send the Certificate of Analysis for that batch.

Good to know

QUESTIONS, ANSWERED

Ibutamoren, a growth hormone secretagogue that acts at the ghrelin receptor. It has published human trial data, which is unusual in this category, but it was never approved as a medicine.

The amount of ibutamoren per capsule, nothing else. We do not recommend a strength, because that would be dosing advice for a compound we sell for research use only.

We do not give post-cycle therapy advice. This is a question for a qualified clinician, not for a shop.

This compound is supplied for laboratory research use only. We do not publish timing, dosing or protocol guidance for human use.

Yes. Growth hormone secretagogues are on the WADA Prohibited List and are detectable.

Yes — identity and purity, per batch, by Janoshik Analytical. Email us the batch number from your pack and we will send that batch's Certificate of Analysis.

MK

RESEARCH COMPOUND

Assayed per batch, certificate on request. £69.99.

I WANT MK-677

Sold as a research compound for laboratory and educational use. Not a medicine; not evaluated by the MHRA, EMA or FDA; not intended to diagnose, treat, cure or prevent any disease. Not for human consumption. Not for use by anyone under 18 or by women who are pregnant or breastfeeding. Prohibited in sport by WADA.

Reference

COMPOUND MONOGRAPH

MK-677 in the UK: buying, legal status and what to check

UK searches for MK-677 come down to three questions: is it legal to buy, who is a trustworthy supplier, and what should a listing show. Ibutamoren has never held a marketing authorisation from the MHRA, so it is not a licensed medicine in the UK, and it is not an authorised food supplement ingredient, so it cannot lawfully be sold or labelled for consumption. Free Muscle supplies it strictly as a research compound to adults aged 18 or over. Growth hormone secretagogues also sit on the WADA Prohibited List. A fuller account of the UK position is on our MK-677 legal status page.

What separates a credible UK listing from a poor one is documentation. Look for a stated strength and capsule count, a batch number on the pack, a certificate of analysis for that batch rather than for the product line in general, a named independent laboratory, plain packaging, tracked delivery and a written returns policy. This listing is our 25mg strength, the highest of the three we make alongside 10mg and 12.5mg. Every batch is assayed by Janoshik Analytical, the batch number is on the label, and the certificate for your batch is sent by email on request. UK delivery is free and tracked, orders placed before 2pm Monday to Friday are processed the same working day, EU orders arrive in three to seven working days, and unopened items can be returned within 30 days. See shipping and our guarantee.

Capsules compared with other forms

MK-677 circulates as capsules, tablets, liquids and raw powder. Ibutamoren mesylate is a stable, orally active small molecule, developed in the 1990s as an orally active drug, so unlike a peptide it was given by mouth in the published studies. The differences between forms concern measurement and stability rather than pharmacology. A capsule holds a fixed weighed fill, which is what the certificate of analysis measures, so the quantity per unit is known and does not depend on a pipette, a dropper or a suspension that has settled. Research liquids rely on the compound staying evenly dispersed and on the solvent surviving light and warmth, and a purity figure for the raw powder says nothing about the concentration of the finished liquid. Raw powder needs an analytical balance, and weighing errors at milligram scale are large in percentage terms. None of this is a claim that one form produces a different outcome.

MK-677 compared with ipamorelin

Both compounds act at the same target, the growth hormone secretagogue receptor GHS-R1a, and both fall under growth hormone secretagogues on the WADA list, but they differ in almost every practical respect. Ipamorelin is a pentapeptide, a chain of five amino acids, which is broken down in the digestive tract and has therefore been studied by injection; MK-677 is a non-peptide molecule designed to be active by mouth. Ipamorelin has a short half-life measured in hours in the reported pharmacokinetics, whereas the MK-677 literature describes a long half-life that allowed once-daily administration in trials. MK-677 has a two-year randomised trial in older adults, a large Alzheimer's disease trial and studies in obesity, catabolism and hip fracture; ipamorelin has early-phase and preclinical work, with a post-operative ileus programme that did not proceed to approval. Neither is a licensed medicine in the UK. The MK-677 trials recorded increased appetite, raised fasting glucose and reduced insulin sensitivity; the ipamorelin literature is too thin to make an equivalent list. Read about ipamorelin on its own page. This is a pharmacological and regulatory comparison, not a recommendation of either compound.

Reading the certificate of analysis for this product

Every batch of Free Muscle MK-677 is assayed by Janoshik Analytical, and the certificate is tied to the batch number on your bottle. Identity is established by chromatography with mass spectrometric or ultraviolet detection, so the certificate should name the method (HPLC, LC-MS or similar) and confirm that the substance detected is ibutamoren rather than something else. Purity is expressed as a percentage of the material tested, and for a capsule product the more useful figure is the measured quantity per capsule set against the label claim, since a pure compound underfilled into a capsule is still a mislabelled product. The batch number on the certificate must match the pack, and the test date must make sense for that batch. A document with no batch number, method, date or laboratory name is a marketing sheet, not an analytical one. To request the certificate for your batch, email us the batch number and the product name. See our lab tests page and How to read a certificate of analysis.

Detection, sport and testing

Ibutamoren is listed by WADA under S2, peptide hormones, growth factors, related substances and mimetics, as a growth hormone secretagogue, and is prohibited at all times, in and out of competition. Laboratories screen for it and its metabolites in urine, and a finding is a violation regardless of intent or source. We have not found a peer-reviewed human excretion study that fixes a detection window, so the honest statement is that it is detectable and the window is not established in the published literature. For anyone subject to anti-doping rules, the conservative position is to regard it as detectable.

Storage, stability and handling

Ibutamoren mesylate is supplied here as a dry capsule fill, and the main threats to a dry solid are moisture, heat and light. Keep the bottle tightly closed in a cool, dry place away from direct sunlight, and do not decant capsules into another container, because the batch number stays with the original label and traceability is lost without it. Handle with clean, dry gloves and clear any spilt powder promptly. Record the batch number and date of opening in the laboratory notebook. Keep out of the reach of children and pets. Refer to any date printed on the label rather than assuming a shelf life.

Glossary

  • Ibutamoren mesylate: the mesylate (methanesulfonate) salt of ibutamoren, the form used in the clinical trials and in most capsule products.
  • Growth hormone secretagogue (GHS): a substance that stimulates the pituitary to release growth hormone.
  • GHS-R1a: the ghrelin receptor, the G-protein-coupled receptor through which ibutamoren and ghrelin act.
  • Ghrelin: the 28-amino-acid stomach peptide identified in 1999 as the natural ligand of GHS-R1a.
  • IGF-1: insulin-like growth factor 1, a hormone made mainly in the liver whose blood level rises when growth hormone secretion rises; used in trials as a marker of drug effect.
  • Certificate of analysis (COA): a laboratory report of identity and purity for one specific batch.
  • WADA S2: the section of the Prohibited List covering peptide hormones, growth factors and their mimetics, including GH secretagogues.

What the published research reports

MK-677 has a substantial clinical literature, and it cuts both ways. In a two-year randomised, placebo-controlled trial in 65 healthy adults aged 60 to 81, daily ibutamoren raised growth hormone and IGF-1 to young-adult levels, and after one year fat-free mass had risen by about 1.1 kg against a 0.5 kg fall on placebo, with no difference in visceral or total fat. Body weight rose more on the drug (2.7 kg against 0.8 kg), fasting glucose increased, insulin sensitivity fell and cortisol rose; the most frequent side effects were increased appetite that subsided within a few months, mild transient leg oedema and muscle pain, and the extra fat-free mass did not translate into better strength or function, although the authors noted the study was too small to assess function (Nass 2008). An eight-week trial in 24 obese men reported roughly a 40 percent rise in IGF-1 and an increase in fat-free mass, with no change in total or visceral fat and an impairment of glucose tolerance on oral testing at both two and eight weeks (Svensson 1998). A phase IIb trial in 123 older patients recovering from hip fracture found IGF-1 rose but most functional measures did not improve, and the trial was stopped early because of a safety signal of congestive heart failure in a small number of patients; the authors described the safety profile in that population as unfavourable (Adunsky 2011). In 563 patients with mild to moderate Alzheimer's disease, a year of treatment raised IGF-1 by about 73 percent yet produced no difference from placebo on any cognitive or functional measure (Sevigny 2008). None of these findings is a claim about this product, which is supplied for laboratory research only.

  • Nass 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):601-611. PMID: 18981485.
  • Svensson 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):362-369. PMID: 9467542.
  • Adunsky 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):183-189. PMID: 21067829.
  • Sevigny JJ, et al. Growth hormone secretagogue MK-677: no clinical effect on AD progression in a randomized trial. Neurology. 2008;71(21):1702-1708. PMID: 19015485.

Related compounds and reading

All strengths and brands of ibutamoren we stock are compared on the MK-677 collection page. Related secretagogue and growth hormone pages: MK-777 (Acetamoren), ipamorelin and HGH (somatropin). Further reading: MK-677: what the research says, MK-677 by brand, What is Janoshik Analytical and Price per milligram.

Supplied for laboratory research use only. MK-677 is not a licensed medicine and has not been evaluated by the MHRA, EMA or FDA. Not a food supplement, not for human consumption, and not for sale to anyone under 18. Nothing on this page is medical, dosing or protocol advice.