MK-677 (Ibutamoren)

MK-677 sits at a 4.5–5.0/10, Neutral score because it is the best-evidenced growth-hormone secretagogue you can name and still not a clear win, which is an unusual place to land. The practical read: if you want oral convenience, deeper sleep, and lean-mass support, and you genuinely accept a certain glucose cost plus a cardiac caveat, it is a reasonable monitored experiment on verified product. If you are chasing proven strength, function, or longevity, the data actively argues against it, and a cleaner path exists. The score is justified because a strong evidence base full of negative results is exactly that, strong and discouraging at the same time. Merck developed MK-677 for years and never brought it to market. Despite evidence of target engagement, it was ineffective at slowing the progression of Alzheimer disease, the cleanest sign that raising IGF-1 is not the same as helping. Sevigny 2008

✅ Best for: Experienced users who value an oral, once-daily option over injections and will not miss the needle. People whose main goals are deeper sleep and lean-mass support rather than maximal strength, since the strength evidence is absent. Older adults with lower baseline growth hormone, who tend to respond more on the hormone markers. Anyone with clean fasting glucose and no cardiac history who will actually track glucose, HbA1c, and IGF-1 on a schedule. Users who can source third-party-tested material and verify identity, given documented mislabeling.

❌ Avoid if: You have diabetes, pre-diabetes, or metabolic syndrome, because MK-677 reliably worsens glucose control. You have heart failure or significant cardiac disease, given the congestive-heart-failure signal that halted a trial and the fluid-retaining mechanism. You have active or prior cancer, since IGF-1 is mitogenic and chronically raising it is a theoretical tumor-promotion risk. You compete in tested sport, since it is banned at all times under WADA category S2. You cannot verify source quality, because grey-market products are frequently mislabeled and sometimes contain other unapproved drugs entirely.