Peptide library / Hormones & metabolism / MK-677
MK-677
An oral growth hormone booster, not a peptide, widely sold alongside peptides.
Effects studied or claimed
What it is used or promoted for, and where each effect has actually been seen
- Growth hormone and IGF-1 elevationSmall human studies
- Muscle mass in older adultsSmall human studies
- Appetite increaseSmall human studies
How it is thought to work
MK-677 activates the ghrelin receptor like GHRP-6 but is a small molecule that works by mouth.
What the evidence shows
Trials in older adults raised IGF-1 and lean mass but did not improve strength or function. A hip fracture trial was stopped early over heart failure concerns.
Safety and unknowns
Increased hunger, water retention, raised blood sugar and insulin resistance.
Regulatory status
Not approved. Banned in sport.
Regulatory status changes quickly. This entry was last reviewed on 27 October 2026. Confirm current status with the FDA before relying on it.
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General information, not medical advice. Do not buy or inject unregulated peptides.