Explore MK-677 (ibutamoren) dosage trends, reconstitution volumes, and vial size patterns from anonymized WPA peptide calculator sessions.
MK-677 (ibutamoren) is an orally bioavailable, non-peptide ghrelin mimetic studied for its sustained elevation of growth hormone and IGF-1 with once-daily dosing. Unlike the injectable GHRPs, it is administered orally as a capsule or in solution rather than reconstituted from a lyophilized vial. This data captures the dose amounts and (where applicable) reconstitution volumes researchers most commonly select when working with MK-677.
MK-677 — also known as ibutamoren or by its developer code MK-0677 — is the only molecule in this entire family that is non-peptide and orally bioavailable, and that single fact defines its position in the GH-secretagogue toolkit. The compound was discovered at Merck in the 1990s by the team led by Roy Smith as a small-molecule ghrelin-receptor (GHS-R1a) agonist — a deliberate effort to find a non-peptide that could activate the same growth-hormone-secretagogue receptor pathway as the injectable GHRPs (GHRP-2, GHRP-6, ipamorelin) without requiring subcutaneous administration.
MK-677 (ibutamoren) is an orally-active growth-hormone secretagogue most often sourced for GH/IGF-1 and body-composition research. It mimics the peptide ghrelin but is itself a small molecule, not a peptide, with a roughly 24-hour effect on GH and IGF-1. It is usually supplied as capsules or an oral liquid; the FDA has warned against marketing it as a dietary supplement.
MK-677 binds and activates the ghrelin receptor (GHSR-1a) in the pituitary and hypothalamus, increasing pulsatile growth hormone (GH) release through both direct pituitary somatotroph stimulation and indirect amplification of endogenous GHRH signalling, with a downstream increase in IGF-1. Ghrelin-receptor activation in the hypothalamus also drives appetite, which is the most-reported subjective effect at consumer doses. Glucose-tolerance worsening and modest insulin resistance are predictable secondary effects of sustained GH/IGF-1 elevation and have been documented in the long-term healthy-elderly trial.
Nass et al. (Ann Intern Med 2008) ran a 2-year randomised placebo-controlled trial of MK-677 25mg/day in healthy elderly adults; the active arm sustained GH and IGF-1 in the young-adult range, increased fat-free mass by ~1.1kg, but did not improve strength or function and worsened fasting glucose and HbA1c. Murphy et al. (J Clin Endocrinol Metab 1998) characterised the GH pharmacodynamics of MK-677. Lumos Pharma is advancing oral MK-677 (LUM-201) in pediatric growth hormone deficiency (OraGrowtH210 and OraGrowtH212 trials), fragile X syndrome, and SHOX deficiency.
MK-677 has a reported half-life of ~24 hours, and the dose intervals researchers model most often fall around once daily. An approximately 24-hour half-life means a single daily dose maintains elevated GH/IGF-1 signalling, with steady state reached over several days. It is catalogued under Muscle Peptides on WPA.
10 MK-677 reconstitution calculations have been logged by the WPA community. The most common dose entered is 10mg (4 calculations). The most common bacteriostatic water volume is 500mL. The most popular vial size is 200mg (9 sessions). The most common dosing frequency is daily (7x/week) (1 logged protocols).
These figures come from anonymized WPA peptide calculator sessions.
All figures shown are aggregated from anonymized calculator inputs and are provided strictly for independent laboratory research and educational purposes. They are community usage statistics — not dosing recommendations, and not medical advice.