MK-677
An oral compound (not a peptide) studied for raising growth hormone and IGF-1.
Growth hormone, in a pill.
MK-677 is the rare growth-hormone booster that works orally. It mimics ghrelin to raise GH and IGF-1 around the clock - which is its appeal and, for some, its drawback, since the elevation is sustained rather than pulsed.
At a glance
Where the research focuses.
GH / IGF-1 elevation
Reliably raises both in humans - its best-documented effect.
Muscle & bone
Studied for lean mass and bone density, with mixed functional results.
Sleep
Often reported to deepen sleep, consistent with GH-axis effects.
Appetite
Increases hunger via ghrelin signalling - sometimes a goal, sometimes not.
Sustained, not pulsed.
Unlike the injectable GH peptides that produce brief pulses, MK-677 keeps GH and IGF-1 elevated continuously - useful for convenience but further from the body's natural rhythm.
It was studied extensively by Merck (including in older adults and frailty) but never brought to approval.
Strength of the evidence.
- Sustained GH / IGF-1 elevation in humans
- Ghrelin-receptor mechanism characterised
- Bone-density and lean-mass signals
- Sleep-quality reports
- Long-term safety
- A heart-failure signal in one elderly trial
How it works
Ghrelin receptor
Oral agonist at GHSR-1a driving GH release.
CharacterisedIGF-1 rise
Downstream IGF-1 elevation underlies most effects.
DocumentedSustained action
Long half-life keeps levels elevated ~24 h.
ClinicalSide effects
Water retention, appetite and reduced insulin sensitivity.
CommonHow it moves through the system
Signs of a quality compound
Despite extensive research, MK-677 was never approved for any use and is sold as an investigational research compound. It is prohibited in competitive sport. Water retention and insulin-sensitivity changes are commonly reported.
- For research purposes only
- Not for human consumption
- Not FDA approved
- Consult a qualified professional