Overview
MK-677 (ibutamoren) is technically a non-peptide compound, but it's almost always discussed within the peptide/GH-secretagogue conversation because it raises growth hormone and IGF-1 and is taken orally rather than injected.
How It's Thought to Work
It mimics ghrelin at the growth-hormone secretagogue receptor, increasing GH and IGF-1 levels. Being orally bioavailable distinguishes it from injectable GHRPs.
What the Research Says
There is a moderate body of human research, including studies in older adults and on body composition, though it remains investigational and was studied by pharma without reaching approval.
Regulatory & Legal Status
Investigational — not FDA-approved. Sold as a research chemical. Prohibited in sport by WADA.
Safety Considerations
Reported effects include increased appetite, water retention, and changes in insulin sensitivity/blood glucose. Not an approved medicine. Consult a qualified clinician.