Research information only, not medical advice. In a one-year randomised trial in healthy older adults, MK-677 raised growth hormone and IGF-1 toward young-adult levels and increased fat-free mass versus placebo. Whether that translates to the muscle or anti-ageing results marketed to younger users is untested.
MK-677's documented result comes from a randomised, placebo-controlled trial in healthy older adults (Nass et al., 2008): over one year, once-daily oral MK-677 raised growth hormone and IGF-1 and significantly increased fat-free mass versus placebo. But it is investigational, the trial was in older adults, and part of the fat-free mass gain reflects fluid retention. Whether the muscle-building or anti-ageing changes marketed to younger, healthy users occur the same way is untested. Research information, not medical advice.
For the full evidence base, clinical trials, and regulatory status, see the Ibutamoren research overview . Related: mk-677 side effects .
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Frequently asked questions
- What does MK-677 do before and after?
- In a one-year trial in older adults it raised growth hormone and IGF-1 and increased fat-free mass versus placebo, though part of that gain was fluid retention. Results in younger users are untested.
- How long does MK-677 take to work?
- The documented trial measured its effect on fat-free mass over one year. It raises growth hormone and IGF-1 relatively quickly, but body-composition change was assessed over months.
Updated · sourced to primary documents