MK-677 + BPC-157 + TB-500 Capsule Bundle

The Yakka Strength MK-677, BPC-157 and TB-500 capsule bundle brings together one growth hormone secretagogue, ibutamoren (MK-677), and two research peptides, BPC-157 and TB-500, all from the same manufacturer and stocked in our Muscle Market range. Yakka Strength lists the pack as 60 capsules and states no content per capsule, so we quote none. Supplied to adults for laboratory research only, not for human consumption.

A bundle is a listing convenience only: it lets products from one manufacturer be ordered in a single purchase. Nothing on this page claims that they act together or should be studied together, and Free Muscle publishes no stack or cycle guidance for any product.

About the compounds in this bundle

MK-677 (Ibutamoren)

Ibutamoren (MK-677, L-163,191, nutrobal) is not a SARM but an orally active ghrelin receptor (GHS-R1a) agonist, a growth hormone secretagogue. Unusually for this market it has real human data. A two-year randomised trial in healthy older adults reported, at one year, sustained rises in growth hormone and IGF-1, about 1 kg more fat-free mass than placebo and no gain in strength or function, alongside increased appetite, fluid retention, higher fasting glucose and reduced insulin sensitivity. Never approved. WADA class S2. Compare brands on the MK-677 (Ibutamoren) collection page.

BPC-157

BPC-157 is a synthetic fifteen-amino-acid peptide based on a sequence from a human gastric protein. Almost all published work is rodent and cell research, largely from one Croatian group, covering animal models of gut, tendon, muscle and vascular injury. No controlled human trial has been published, and oral absorption of any peptide is unproven. WADA lists it under S0 (non-approved substances). Compare brands on the BPC-157 collection page.

TB-500 (Thymosin Beta-4 fragment)

TB-500 is the trade name for a synthetic fragment of thymosin beta-4, a 43-amino-acid actin-binding peptide present in most human and animal cells. Reviews of thymosin beta-4 cover preclinical wound, corneal and cardiac repair models and early clinical trials of the full peptide. TB-500 itself has no published human data. WADA names thymosin beta-4 and its derivatives, including TB-500, under S2. Compare brands on the TB-500 (Thymosin Beta-4 fragment) collection page.

The three molecules side by side

The size gap, roughly tenfold, shapes how each is delivered, identified and detected. The two peptides are in capsule form. Oral absorption of peptides is unproven, a point covered in our article Do oral peptides actually work?.

This listing

• Brand: Yakka Strength (third-party brand, Muscle Market)
• Compounds: ibutamoren (MK-677), BPC-157, TB-500
• Form and pack size: 60 capsules, as listed by the manufacturer
• Content per capsule: not stated by the manufacturer
• COA: only where Yakka Strength supplies one for the batch held
• Sold to adults aged 18 and over, for laboratory research only

Without a stated content for any of the three compounds, milligrams per pack cannot be calculated, so this bundle cannot be set against single-compound packs on cost per milligram (the method is explained in price per milligram). Yakka Strength also lists MK-677, BPC-157 and TB-500 singly.

MK-677, BPC-157 and TB-500 in the UK: buying, legal status and what to check

Searches such as "MK677 UK buy", "BPC 157 UK legal" and "BPC157 TB500 UK" ask two things: can these be bought lawfully here, and does the seller document what it sells?

The legal position for each compound

None of the compounds on this page is a licensed medicine in the United Kingdom, none has been assessed by the MHRA and none is an authorised food supplement. None is a controlled drug either, which is why they can be supplied at all, but lack of control is not approval: they cannot lawfully be sold for human consumption under any heading. Free Muscle supplies them to adults aged 18 and over for laboratory research only. None is available on prescription. MK-677 and TB-500 fall under WADA class S2, and BPC-157 under S0. Buyers are responsible for the rules that apply to them, including any anti-doping code. See our MK-677 legal status page. Our SARMs research guide has more background.

What a bundle listing should document

Every claim on a bundle has to hold for each compound separately. A well-documented UK bundle listing shows:

• Each compound named properly, with the manufacturer identified.
• A lot number on every container, since a certificate can only be tied to material that carries its number.
• A separate certificate for each compound; a report on the MK-677 capsules proves nothing about the peptides, and the reverse.
• A stated content per capsule for each compound, or a clear note that the manufacturer gives none.
• Sale terms that match research supply: an 18+ restriction and no directions or outcome claims.
• A traceable UK company, tracked delivery, plain packaging and published returns terms.

Where this listing stands

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 compound points rest with Yakka Strength. The label states no content for any of the three, so that check is not met, and a certificate is shown only where the manufacturer supplies one for the batch we hold. Reviews and forum threads cannot close either gap: they record impressions, not measured content. Our UK supplier checklist sets out the full list of checks.

Capsules compared with other forms

All three compounds circulate as capsules, tablets and liquids, and the two peptides also as freeze-dried powder in vials. The molecule is the same in each; what differs is whether research used that route and how the material keeps.

• Ibutamoren is the exception in this bundle. It was designed by Merck as a non-peptide so that it would remain active when swallowed, and the controlled trials cited here gave it by mouth.
• BPC-157 was mostly given by injection into the abdominal cavity in rodent work, with some studies adding it to drinking water. No study has measured blood levels in people after a capsule, and the question is examined in BPC-157 capsules vs injection: what the studies used.
• TB-500 and thymosin beta-4 were studied by injection or local application to eye, skin or heart tissue. No oral study of either has been published.

For the peptides the obstacle is digestion: pepsin, trypsin, chymotrypsin and brush-border peptidases split peptide bonds, and short linear chains are routine substrates. Ibutamoren has no peptide bonds for them to cut.

Dry formats generally keep better than solutions, where hydrolysis and microbial growth can start. A capsule's content is fixed at blending and filling, so its consistency depends on the blend, which only a per-capsule content test shows; a liquid's depends on complete dissolution and accurate measuring. None of this implies that any format produces an effect.

MK-677 compared with ipamorelin

The compound most often searched against MK-677 is ipamorelin ("ibutamoren vs ipamorelin"). The two peptides in this bundle act by unrelated mechanisms, whereas ipamorelin shares MK-677's receptor, which makes it the useful reference point.

Mechanism is where they meet. Both bind the ghrelin receptor on the pituitary and release growth hormone the gland already holds, rather than supplying hormone from outside. The 1998 paper from Novo Nordisk that introduced ipamorelin described it as the first selective secretagogue: in conscious swine it released growth hormone with a potency similar to the older peptide GHRP-6, but unlike GHRP-6 and GHRP-2 it did not raise ACTH or cortisol beyond the levels seen with growth hormone releasing hormone. That is an animal finding, not a human one.

Evidence is where they part. Ibutamoren has randomised human trials with recorded adverse findings; ipamorelin's human literature is much thinner, and a PubMed search combining the two names returns no randomised trial comparing them, so neither can be ranked above the other. Brands held are in the ipamorelin collection, the two are set against prescription somatropin in MK-677 vs ipamorelin vs somatropin, and the peptide's own studies are in the ipamorelin research guide.

Reading the certificate of analysis for this product

Yakka Strength is a third-party brand sold through Muscle Market. For third-party brands we display a certificate of analysis only where the manufacturer supplies one for the exact batch we hold; if none is shown, none has been supplied and we do not substitute a generic document. Free Muscle-brand products, by contrast, are assayed batch by batch at Janoshik Analytical, with the certificate sent on request by email. Our lab testing page explains what a certificate shows.

Three compounds means three results. Read each against its container:

• Which compound. A result headed only with the bundle name cannot show which of the three was measured.
• Identity, by HPLC or LC-MS. HPLC matches a peak to a reference standard's retention time; LC-MS also weighs it, which is firmer. The expected masses differ widely: ibutamoren gives a protonated ion near m/z 529, BPC-157 has a molecular weight of about 1419.5, and TB-500 should match the mass of the fragment stated on the report, far below the full 4,963 g/mol protein.
• Purity (%). The compound's share of the chromatogram: cleanliness, not quantity.
• Content per capsule. The only line that can supply the figure this label leaves out. For peptides, check whether it reports net peptide or total powder.
• Batch number, test date and laboratory. Check the number against the lot printed on that compound's container; a named laboratory and a dated report can be checked, an anonymous one cannot.

Without an identity line nothing confirms the compound; without a content line the strength stays unknown; without a matching batch number the report describes other material. Contact us with the batch numbers and we will say what exists for current stock. See also how to read a certificate of analysis.

Detection, sport and testing

All three compounds are prohibited at all times, in and out of competition, under the World Anti-Doping Code, which UK Anti-Doping applies in this country. They sit in different sections. Ibutamoren is named among the growth hormone secretagogues in S2. TB-500 falls under S2 because the list names thymosin beta-4 and its derivatives. BPC-157 is named in S0, the section for substances with no current approval for human therapeutic use. Strict liability applies: an athlete answers for any prohibited substance in a sample, whatever the label said.

For BPC-157, the Salt Lake City anti-doping laboratory published a validated urine method in 2017 with a limit of detection of 0.1 ng/mL, found the peptide stable in urine for at least four days, and made the test more specific by measuring a stable metabolite alongside it. None of the studies cited on this page sets out how long any of the three compounds remains detectable in human urine after exposure, so the accurate statement for each is: detectable, window not established. Anyone subject to testing should assume that exposure to any compound in this bundle will be found.

Storage, stability and handling

No published stability study covers any of these compounds in capsule form, so the expiry or best-before date printed by the manufacturer, where there is one, is the limit to work to. For the two peptides, moisture is the main threat, because water hydrolyses peptide bonds. Full thymosin beta-4 also contains a methionine residue, which oxidises readily, a process light can speed up. For all three, damp softens capsule shells and clumps powder, while dry heat makes shells brittle.

Keep each container closed in a cool, dry, dark cupboard, away from radiators and steamy rooms, with any desiccant left in place. If containers are refrigerated, let them reach room temperature before opening so condensation does not form inside. Keep the contents in the original, lot-numbered packaging and note the date of first opening. Handle the contents as laboratory reagents: gloves for opened capsules, separation from food and drink, storage out of reach of children and animals, and disposal as chemical waste rather than in household bins or drains.

Glossary

• Growth hormone secretagogue: a substance that causes the pituitary gland to release more of its own growth hormone; ibutamoren and ipamorelin are both examples.
• GHS-R1a: the receptor for the stomach hormone ghrelin, found on the pituitary and elsewhere; ibutamoren binds it.
• IGF-1: insulin-like growth factor 1, a hormone made mainly in the liver whose blood level follows growth hormone output.
• Pentadecapeptide: a peptide of 15 amino acids, which is how BPC-157 is described.
• Thymosin beta-4: the full 43-residue actin-binding protein from which the TB-500 fragment is taken.
• Peptidase: any enzyme that splits a peptide chain; pepsin and trypsin are two of the digestive ones.
• Retention time: the point at which a compound emerges from an HPLC column; a match with a reference standard supports, but does not prove, identity.
• S0 and S2: WADA list sections; S0 catches substances with no human therapeutic approval, S2 covers peptide hormones, growth factors and their releasing agents.
• Strict liability: under the anti-doping code, a banned substance in a sample counts as a violation regardless of intent or labelling.

Related

• MK-677 (Ibutamoren) collection
• BPC-157 collection
• TB-500 (Thymosin Beta-4) collection
• Ipamorelin collection
• Yakka Strength brand page
• Bundles collection
• Research articles: MK-677, BPC-157, TB-500
• Delivery and returns

Supplied for laboratory research use only. Not a medicine, not evaluated by the MHRA, EMA or FDA, and not for human consumption. Buyers must be 18 or over. Nothing on this page is medical or dosing advice or a recommendation to use, stack or cycle any compound; research summaries describe findings in study participants or animals, not claims about this product.

References

1. 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):601-11. PMID: 18981485.
2. Sikiric P, et al. Brain-gut Axis and Pentadecapeptide BPC 157: Theoretical and Practical Implications. Curr Neuropharmacol. 2016;14(8):857-865. PMID: 27138887.
3. Goldstein AL, et al. Thymosin beta4: a multi-functional regenerative peptide. Basic properties and clinical applications. Expert Opin Biol Ther. 2012;12(1):37-51. PMID: 22074294.
4. Raun K, et al. Ipamorelin, the first selective growth hormone secretagogue. Eur J Endocrinol. 1998;139(5):552-61. PMID: 9849822.
5. Cox HD, et al. Detection and in vitro metabolism of the confiscated peptides BPC 157 and MGF R23H. Drug Test Anal. 2017;9(10):1490-1498. PMID: 28035768.