In the published trials, the most consistently reported effects of MK-677 were increased appetite, water retention or edema, and fatigue. Because it raises growth hormone, it also nudged metabolic markers: fasting blood glucose rose and insulin sensitivity declined in the 2-year older-adult trial.[1][2][3]
Reviewed for accuracy · Last reviewed July 8, 2026The metabolic signal matters. Higher fasting glucose and reduced insulin sensitivity are relevant for anyone with, or at risk of, impaired glucose regulation. Beyond that, a hip-fracture trial was stopped early over a congestive-heart-failure safety signal, and the large Alzheimer's trial, while showing the expected IGF-1 rise, did not produce clinical benefit, which tempered enthusiasm for the compound.
Increased appetite often eased within a few months in the older-adult trial. Because MK-677 raises blood glucose and can cause fluid retention, monitoring and medical oversight are commonly discussed, especially for anyone with metabolic or cardiovascular concerns.
This page is an independent educational reference and is not medical advice, and does not indicate any approval status for any use. MK-677 is a non-peptide research compound and is not FDA-approved. Talk to a doctor before starting any compound.