MK-677 (Ibutamoren)

MK-677 (Ibutamoren) isn't technically a peptide — it's a small molecule you can take as a pill that mimics ghrelin, your "hunger hormone." The result? Your body produces more growth hormone naturally, without injections. **Why is that significant?** Most growth hormone-releasing compounds require injections. MK-677 is one of the few that works orally, making it much more convenient. One daily dose keeps growth hormone and IGF-1 elevated for 24 hours. **What the research shows:** • Increases growth hormone and IGF-1 levels significantly • May improve sleep quality (GH is released during deep sleep) • Could help preserve muscle mass and bone density • Studied for elderly populations with age-related decline • Does NOT suppress your natural GH production **The trade-off:** Because MK-677 mimics ghrelin, it increases appetite — sometimes significantly. It can also cause water retention and may affect blood sugar in some people. **Clinical research:** Studied in clinical trials for muscle wasting, hip fracture recovery, and growth hormone deficiency, but never received FDA approval. **Important to know:** MK-677 is banned by WADA and not approved for any medical use. Long-term safety data is limited. --- **Sources:** Nass R, et al. (2008) Journal of Clinical Endocrinology & Metabolism | Murphy MG, et al. (1998) Journal of Clinical Endocrinology & Metabolism

Despite decades of study, no phase 3 program succeeded and MK-677 is not approved. Trials used clinical doses (e.g., 25 mg/day) with meaningful side effects, and functional outcomes (strength, mobility) were not improved in the pivotal elderly study. Gray-market use is unregulated.

Orally bioavailable ghrelin mimetic that activates GHS-R1a, boosting GH pulsatility and IGF-1 with once-daily dosing; phase 2 trials used ~25 mg/day. Note: it is a small molecule, not a peptide.