Is MK-677 (ibutamoren) legal in the US?
No. It is not approved and is sold as a research chemical.
Not approved by the FDA for any use. MK-677 (ibutamoren) is an investigational compound that Merck and later Lumos Pharma studied but never submitted for approval. The FDA placed ibutamoren mesylate in Category 2 of its compounding bulk-substances list, meaning significant safety risks, and reviewed it at a Pharmacy Compounding Advisory Committee meeting in October 2024. It is sold online as a research chemical. 1
No. Merck and later Lumos Pharma studied it, and no one ever submitted it for approval. The FDA has flagged it as a significant safety risk for compounding. 1
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More on MK-677 (ibutamoren)
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.