Does MK-677 (ibutamoren) work?
Partly: two controlled trials, of 65 and 563 people, with small or no real benefit.
Two randomized placebo-controlled trials are cited: a two-year trial in 65 healthy older adults that raised growth hormone and IGF-1 and increased fat-free mass, and a 563-patient trial in Alzheimer's disease that raised IGF-1 but did not slow decline. Those are real controlled human data, which is B, but the muscle-building use it is sold for has only the 65-person trial, with modest body composition changes and no strength or function benefit. 45
A two-year randomized, double-blind, placebo-controlled trial enrolled 65 healthy adults aged 60 to 81. Daily MK-677 raised growth hormone and IGF-1 to young-adult levels. Fat-free mass rose by 1.1 kg, versus a 0.5 kg fall on placebo. But visceral fat and total fat did not change. Limb fat increased more, and body weight rose 2.7 kg. Strength, function and quality of life did not improve. Fasting glucose rose and insulin sensitivity fell. 5
A 12-month randomized trial enrolled 563 patients with mild to moderate Alzheimer's disease. It tested the idea that raising IGF-1 would slow decline. IGF-1 rose by 60 to 73 percent, so the drug did work on its target. But it made no difference from placebo on any thinking or daily-function measure. 4
Evidence checklist
- Randomised controlled trial Two placebo-controlled trials
- Human study over 100 people 563 patients in the Alzheimer's trial
- More than one research group Merck-linked trials only
- Clinical outcomes, not surrogate markers Mostly IGF-1 and body composition
- Human safety data beyond case reports Glucose rise seen in controlled trials
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Citations
- FDA: Bulk drug substances nominated for use in compounding under section 503A, category list fda.gov
- Nass 2008, Ann Intern Med: Effects of an oral ghrelin mimetic on body composition in healthy older adults (DOI) doi.org
- Sevigny 2008, Neurology: MK-677 no clinical effect on AD progression (DOI) doi.org
- Sevigny 2008, Neurology: Growth hormone secretagogue MK-677, no clinical effect on AD progression pubmed.ncbi.nlm.nih.gov
- Nass 2008, Ann Intern Med: Effects of an oral ghrelin mimetic on body composition and clinical outcomes in healthy older adults pubmed.ncbi.nlm.nih.gov
Reference information only, not medical advice. Drawn from the MK-677 (ibutamoren) article, fact-checked against the cited sources. No dosing anywhere on this site.