MK-677 (ibutamoren)
Muscle Building · Oral ghrelin receptor agonist
Tier C
What this is
The only orally active ghrelin/GH-secretagogue used widely in biohacker circles. Merck halted development after Adunsky 2011 hip fracture trial showed excess heart failure events in elderly subjects. Hunger and water retention well-documented in short-term use. Strong insulin resistance signal.
Mechanism
Non-peptide ghrelin mimetic; orally bioavailable GHS-R1a agonist; raises GH and IGF-1 sustainably for ~24 hr per dose; Merck-originated, abandoned after Ph2/3 hip fracture study showed elevated HF risk
Dose & route
Typical illicit: 10-25 mg PO daily
Citations
- https://pubmed.ncbi.nlm.nih.gov/18541703/
- https://pubmed.ncbi.nlm.nih.gov/21576340/
- https://pubmed.ncbi.nlm.nih.gov/9467553/
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This is an independent synthesis of published research by a non-clinician. Scores are opinions supported by citations, not prescriptions. See the full disclaimer and methodology for how this score was produced and what it does and doesn't mean.