MK-677 · Research brief

Where to Buy MK-677 (Ibutamoren) | Research Sourcing

Real Peptides Research TeamEditorial

Updated September 8, 20269 min read

49 WORDS

Short answer

MK-677 is not a peptide. It is not a SARM either, despite sitting next to both in most online catalogs. Ibutamoren is a non-peptide, orally active small molecule that switches on the ghrelin receptor, and that one structural fact changes how it is stored, tested, labelled and legally classified.

Key takeaways

Ibutamoren (MK-677) is a non-peptide, orally active agonist at the ghrelin receptor GHS-R1a, which makes it neither a peptide nor a SARM despite how it is usually catalogued.
In the 2008 Annals of Internal Medicine trial, 25 mg of oral ibutamoren daily for 12 months raised GH and IGF-1 and increased fat-free mass by roughly one kilogram, while fasting glucose rose and insulin sensitivity fell.
MK-677 has no FDA approval for any indication and is not a lawful dietary supplement ingredient in the United States.
The World Anti-Doping Agency prohibits growth hormone secretagogues, including ibutamoren, at all times under section S2.
A JAMA analysis of 44 SARM products sold online found fewer than half contained the labelled compound, which is why batch-matched documentation matters more than price when you buy MK-677 (Ibutamoren).
HPLC purity and mass spectrometry identity are two different tests, and a credible certificate of analysis reports both.

Our team fields sourcing questions on this compound almost daily, and the pattern never changes: buyers spend their time comparing prices and almost none comparing documentation. That is backwards.

Where can researchers buy MK-677 (Ibutamoren)?

Laboratories buy MK-677 (Ibutamoren) from research chemical suppliers that publish batch-specific certificates of analysis showing both HPLC purity and mass spectrometry identity. Ibutamoren holds no FDA approval for any indication and is supplied strictly for laboratory research, never for human or veterinary use. Match the lot number on the certificate to the vial label before purchase.

The harder question is not where to buy MK-677 (Ibutamoren), it is how to confirm that what arrived is actually ibutamoren. A 2017 analysis published in JAMA examined 44 products sold online as SARMs and found that fewer than half contained the compound listed on the label. This article covers what the trial literature reports about ibutamoren, its legal and anti-doping classification, and how to read a certificate of analysis so a supplier claim can be checked rather than trusted.

What ibutamoren is, and what the trial record actually shows

Ibutamoren (MK-677, originally coded MK-0677 at Merck) is a growth hormone secretagogue: a small molecule that acts as an agonist at the growth hormone secretagogue receptor type 1a (GHS-R1a), the same receptor targeted by the stomach hormone ghrelin. Binding at GHS-R1a in the pituitary and hypothalamus amplifies the natural pulsatile release of growth hormone, which in turn raises hepatic output of insulin-like growth factor 1 (IGF-1). Because it is orally bioavailable, it needs no reconstitution, which separates it sharply from injectable peptide secretagogues such as GHRP-2.

What did the trials show? The most cited is a randomised, placebo-controlled trial published in Annals of Internal Medicine in 2008, in which healthy older adults received 25 mg of oral ibutamoren daily for one year. GH and IGF-1 rose into the range typical of healthy young adults, and fat-free mass increased by roughly one kilogram against placebo, with no significant change in total fat mass. Fasting blood glucose rose slightly and insulin sensitivity fell. A separate randomised trial published in Neurology the same year tested MK-677 in Alzheimer's disease and reported no slowing of disease progression.

So is MK-677 effective? At its pharmacological target, yes, and consistently so. At clinical endpoints, the record is thin and partly negative, which is why no regulator anywhere has approved it. Is MK-677 safe? That question has no approved answer: published work reports increased appetite, transient lower-limb edema, muscle pain and reduced insulin sensitivity, and no agency has reviewed it for safety in any population. Anyone about to buy MK-677 (Ibutamoren) for bench work should read those two papers first.

Legal classification, doping bans and the phrase that carries the weight

Ibutamoren is not a federally scheduled controlled substance in the United States, but it is also not an approved medicine and not a lawful dietary supplement ingredient. The FDA has stated that body-building products containing SARMs and similar unapproved investigational compounds fall outside the dietary supplement definition, and has issued warning letters to companies marketing them for human use. So is MK-677 legal, and can you buy MK 677 at all? In the United States, yes when it is sold and purchased as a research chemical for laboratory use only, and no when it is marketed or bought for human consumption. That distinction is the entire legal architecture around this molecule.

In sport the answer is blunter. The World Anti-Doping Agency prohibits growth hormone secretagogues, ibutamoren included, at all times under section S2, in and out of competition. A positive test does not care what the vial label said.

Jurisdiction matters too. Several countries, including Australia, have moved SARMs and growth hormone secretagogues into prescription-only or controlled categories, so import rules diverge substantially from the US position. Researchers who buy MK-677 (Ibutamoren) across borders should check the destination country's import schedule before an order ships, not after customs holds it.

The information here is educational and describes published research findings. Ibutamoren is not an approved human or veterinary product, and questions about animal health belong with a licensed veterinarian rather than a research chemical catalog.

Reading a certificate of analysis instead of trusting a product page

A certificate of analysis is only useful when it reports two separate things: purity and identity. HPLC (high performance liquid chromatography) tells you what percentage of the sample sits under a single chromatographic peak. It does not tell you which compound that peak is. Mass spectrometry does, by confirming the measured molecular weight against ibutamoren's expected mass. A COA showing 99% purity with no identity data is half a document, and that gap is the most common problem we see when clients forward paperwork before they buy MK-677 (Ibutamoren).

Here is the part most sourcing guides skip entirely. Because ibutamoren is a small molecule and not a peptide, it is frequently supplied pre-dissolved in a carrier such as PEG-400, propylene glycol or ethanol rather than as a lyophilised powder. Solutions are convenient, and they are also where concentration drift begins: solvent evaporation at the cap thread, incomplete dissolution at the base of the vial, and repeated warming and cooling all push the real concentration away from the printed number. Powder weighed fresh at the bench removes that variable completely.

Storage follows the same logic. Ibutamoren powder is stable stored cool, dry and shielded from light, while solutions carry a shorter usable window and should be dated the day they are made. Every batch supplied through Real Peptides is small-batch synthesised and ships with its own lot-specific certificate, including the MK 677 listing.

Where to buy MK-677 (Ibutamoren): comparing the four supply channels

Not every source that lists ibutamoren operates to the same documentation standard, and the differences show up in what you can verify rather than what you are told. This table compares the four channels researchers use most when they buy MK-677 (Ibutamoren).

Supply channel	Documentation typically provided	Identity verification possible	Regulatory position	Bottom line
Dedicated research chemical supplier	Batch-specific COA with HPLC purity and mass spectrometry identity, lot number printed on the vial	Yes, the vial lot can be matched directly to the certificate	Sold research use only, not for human or veterinary consumption	Strongest option for laboratory work because the paperwork is auditable, which is the only property that matters at the bench
General online marketplace listings	Generic COA image reused across many listings, usually with no lot number	No, the document cannot be tied to the vial received	Frequently marketed with human-use language, which is where enforcement pressure sits	Avoid entirely; an unmatched certificate is marketing collateral, not analytical data
Overseas bulk API sellers	Manufacturer certificate for a large production lot, sometimes genuine	Partially, but repackaging breaks the chain of custody	Import restrictions apply and vary sharply by destination country	Workable only if you re-test in house; customs risk and identity risk are both real
Retail 'GH support' supplements	Supplement facts panel, no analytical data at all	No, and ibutamoren is not a lawful supplement ingredient in the US	FDA has issued warning letters over body-building products containing unapproved compounds	Not a research source; label claims and actual contents diverge often

What If: Ibutamoren Sourcing Scenarios

What if a supplier will not provide a batch-specific certificate of analysis?

Source elsewhere. A generic certificate reused across every listing proves nothing about the vial in your hand, because purity and identity are batch properties, not brand properties. Legitimate suppliers print a lot number on the label and issue analytical data tied to that lot. When a request for batch documentation is met with a stock PDF or silence, the material is uncharacterised, and uncharacterised material is unusable for research. This is the fastest single filter to apply before you buy MK-677 (Ibutamoren) from any unfamiliar source.

What if the ibutamoren arrives pre-dissolved instead of as a powder?

Date the vial on arrival and treat the stated concentration as provisional. Solutions in PEG-400, propylene glycol or ethanol lose accuracy through solvent evaporation and incomplete dissolution, so a bottle held for months may no longer deliver what the label claims. Powder weighed fresh removes that uncertainty. If solution is what arrived, keep it sealed, cool and dark, and verify concentration in house whenever the experiment depends on precision rather than approximation.

What if the label reads MK-0677 or ibutamoren mesylate instead of MK-677?

Those are the same compound under three different names. MK-0677 is the original Merck development code, ibutamoren is the international nonproprietary name, and ibutamoren mesylate is the salt form used in most research material. Molecular weight differs between the free base and the mesylate salt, which changes concentration calculations, so confirm which form the certificate reports. Name variation on its own is not a red flag. A missing or mismatched molecular weight on the COA is.

What if the research design involves human subjects?

Ibutamoren cannot lawfully be administered to humans outside an authorised clinical trial. In the United States that requires an Investigational New Drug application accepted by the FDA and approval from an institutional review board before anything is given to a participant. Research chemical suppliers sell for laboratory use only and cannot supply material for human administration under any circumstances. Researchers who buy MK-677 (Ibutamoren) from a laboratory supplier and administer it to a person sit outside both the supplier's terms and federal law.

The Unglamorous Truth About Ibutamoren Supply

Here's the honest answer: ibutamoren is cheap to synthesise and easy to counterfeit, and the market reflects both facts. The pharmacology has been characterised for more than two decades and is not in dispute. The bottleneck is the chain of custody between a synthesis reactor and your bench. So is MK 677 worth it? As an orally active, long-studied GHS-R1a probe, it earns its place in a research catalog. As a purchase decision, the price gap between a documented batch and an undocumented one is trivial next to six weeks of work run on material that was never ibutamoren.

Most people who buy MK-677 (Ibutamoren) and end up with useless material were not overcharged. They were undersold on paperwork, which is quieter and far harder to notice until an assay refuses to replicate. The molecule has been studied since the 1990s and behaves predictably at its receptor; what varies wildly across the market is whether the powder in the vial matches the name on the label. Judge a supplier on one habit: whether the certificate names a lot number you can match to the vial, and whether identity was tested at all. That single check removes most of the market from consideration.

References

Peer-reviewed sources on MK-677 (Ibutamoren) indexed in PubMed, listed for research context. Real Peptides supplies MK-677 (Ibutamoren) for laboratory research use only.

Hepatotoxicity induced by MK-677. BMJ case reports, 2025. PMID 40675653. doi:10.1136/bcr-2025-265728
LGD-4033 and MK-677 use impacts body composition, circulating biomarkers, and skeletal muscle androgenic hormone and receptor content: A case report. Experimental physiology, 2022. PMID 36303408. doi:10.1113/EP090741
Effect of the Orally Active Growth Hormone Secretagogue MK-677 on Somatic Growth in Rats. Yonsei medical journal, 2018. PMID 30450851. doi:10.3349/ymj.2018.59.10.1174
Growth hormone secretagogue MK-677: no clinical effect on AD progression in a randomized trial. Neurology, 2008. PMID 19015485. doi:10.1212/01.wnl.0000335163.88054.e7
MK-677, an orally active growth hormone secretagogue, reverses diet-induced catabolism. The Journal of clinical endocrinology and metabolism, 1998. PMID 9467534. doi:10.1210/jcem.83.2.4551
Prolonged oral treatment with MK-677, a novel growth hormone secretagogue, improves sleep quality in man. Neuroendocrinology, 1997. PMID 9349662. doi:10.1159/000127249
Design and biological activities of L-163,191 (MK-0677): a potent, orally active growth hormone secretagogue. Proceedings of the National Academy of Sciences of the United States of America, 1995. PMID 7624358. doi:10.1073/pnas.92.15.7001

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Questions

Buy from research chemical suppliers that issue batch-specific certificates of analysis with both HPLC purity and mass spectrometry identity data, and that print the matching lot number on the vial. Ibutamoren is supplied for laboratory research only. Marketplace listings and supplement retailers cannot document what is actually in the container.

Yes, in the United States ibutamoren can be bought and sold as a research chemical for laboratory use, because it is not a federally scheduled controlled substance. It cannot lawfully be marketed or purchased for human consumption, since it is not an approved drug and not a legal dietary supplement ingredient.

Ibutamoren (MK-677, originally MK-0677) is a non-peptide, orally active growth hormone secretagogue. It acts as an agonist at the ghrelin receptor GHS-R1a in the pituitary and hypothalamus, amplifying pulsatile growth hormone release and raising IGF-1. It is not a SARM and not a peptide, despite common cataloguing.

In the United States MK-677 is legal to sell and purchase as a research chemical for laboratory use, and is not a scheduled controlled substance. It is illegal to market for human consumption because it holds no FDA approval. Several countries, including Australia, apply prescription-only or controlled classifications instead.

No regulator has reviewed ibutamoren for safety in any population, so no supplier can make a safety claim about it. Published trials reported increased appetite, transient lower-limb edema, muscle pain, higher fasting glucose and reduced insulin sensitivity. It is supplied for laboratory research only, never for human or veterinary use.

As a research tool, ibutamoren is a well-characterised and orally active GHS-R1a probe with two decades of published literature behind it, which makes it useful at the bench. Its value depends almost entirely on sourcing, since undocumented material can invalidate weeks of work regardless of how cheaply it was bought.

Yes at its pharmacological target. The 2008 Annals of Internal Medicine trial found that 25 mg of oral ibutamoren daily raised GH and IGF-1 in healthy older adults into the range typical of young adults over 12 months. Clinical endpoint results have been far less consistent, including a negative Alzheimer's trial published in Neurology.

All three act at the GHS-R1a receptor, but MK-677 is a non-peptide small molecule with oral bioavailability, while GHRP-2 and ipamorelin are peptides that degrade in the gut. That means MK-677 requires no reconstitution and is often supplied as powder or solution rather than lyophilised vials, and its receptor stimulation is far longer in duration.

Pricing varies widely by supplier, quantity and whether the material ships with full analytical documentation. Undocumented material is consistently cheaper, which is precisely the problem: the saving is small compared to the cost of running experiments on a compound whose identity was never confirmed by mass spectrometry.

Yes. The World Anti-Doping Agency lists growth hormone secretagogues, including ibutamoren, under section S2 as prohibited at all times, in and out of competition. Accredited laboratories screen for it directly, and a research-use label on the vial has no bearing on an anti-doping result.

Powdered ibutamoren is stable when kept cool, dry and protected from light in a sealed container. Material supplied pre-dissolved in PEG-400, propylene glycol or ethanol has a shorter usable window, loses accuracy through solvent evaporation, and should be dated on the day it is prepared or received.

RESEARCH USE ONLY · NOT EVALUATED BY THE FDA