Peptide data sheet
MK-677
Performance · Ibutamoren · Ibutamoren mesylate · MK-0677
Verdict
unprovenThe unproven label reflects a real but narrow evidence base: MK-677 reliably raises growth-hormone and IGF-1 markers in human studies, but the downstream benefits people want are not established, and safety signals in older and frail populations are a genuine open question.
By MrPepTalks Editorial
Reviewed for scientific accuracy · research information, not medical advice
Last updated Reviewed
Quick answer
MK-677 (ibutamoren) is an orally active growth-hormone secretagogue that acts as a ghrelin-receptor agonist. It is commonly researched for raising growth hormone and IGF-1 and, downstream, for appetite, body composition, and sleep. Human studies confirm it elevates those hormone markers, but the real-world benefits people hope for are not established. It is not FDA-approved and is sold for research use only.
- Class
- Growth-hormone secretagogue / ghrelin (GHS-R) receptor agonist (non-peptide small molecule)
- Half-life
- roughly 4 to 6 hours (reported)
- FDA status
- Not FDA-approved. Investigated in clinical trials but never approved for any use; sold for laboratory research use only.
- WADA banned?
- Yes
Which form actually works?
Oral (capsule / liquid)
Unproven
The form used in nearly all the human research and the one people ask about most. Its selling point is that it is orally active, unlike most injectable research peptides. This is where the hormone-marker data lives, and also where the reported side effects such as water retention and raised appetite show up.
Third-Party Testing & Certificate of Analysis (COA)
A certificate of analysis (COA) is a lab document that reports what a specific batch of material actually contains. Reputable research suppliers publish one for every batch, tied to a lot number you can match against the vial you received.
- HPLC — purity
- High-performance liquid chromatography reports purity as a percentage: how much of the sample is the intended compound rather than impurities.
- Mass spectrometry (MS) — identity
- Mass spectrometry confirms identity by measuring the sample's molecular mass, so it matches the peptide the label names.
It also matters who ran the test. In-house results come from the seller's own lab; an independent third-party lab has no stake in the result, so its COA generally carries more weight. Look for a named testing laboratory, a batch or lot number, and a test date that lines up with the vial in hand.
New to reading one? This guide walks through a COA line by line: how to read a peptide COA.
Sources
- Nass R et al. Effects of an oral ghrelin mimetic (MK-677) on body composition and clinical outcomes in healthy older adults: a randomized trial. Ann Intern Med. 2008;149(9):601-611.
- Murphy MG et al. Oral administration of the growth hormone secretagogue MK-677 increases markers of bone turnover in healthy and functionally impaired elderly adults. J Bone Miner Res. 1999;14(7):1182-1188.
- 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.
Related peptides
All Performance →Frequently asked questions
No spam. Compliant with CAN-SPAM (US), CASL (Canada) & GDPR (EU) · one-click unsubscribe. See our Privacy Policy.