What is MK-677 12.5MG (60 capsules)?
MK‑677 (Ibutamoren mesylate) tablets are an orally active, non-peptide small molecule designed as a ghrelin receptor (GHS‑R1a) agonist and growth hormone secretagogue. In research models, MK‑677 stimulates endogenous growth hormone (GH) and insulin-like growth factor‑1 (IGF‑1) secretion while preserving physiological pulsatility and showing minimal impact on cortisol levels. Its oral bioavailability and sustained activity make it a key compound for exploring endocrine and metabolic pathways in laboratory settings.
Chemical Structure of MK-677 12.5MG (60 capsules)
MK‑677 is a small-molecule growth hormone secretagogue with a spiro-aminoamide backbone, rather than a peptide structure. It has the chemical formula C₂₇H₃₆N₄O₅S and a molecular weight of approximately 528.7 Da. PubChem lists the compound under CID 9939050 (free base) and CID 178024 (mesylate salt), with synonyms including MK‑677, MK‑0677, Oratrope, and L‑163,191.
What Are the Effects of MK-677 12.5MG (60 capsules)?
Research studies indicate that MK‑677:
- Stimulates GH and IGF‑1 Secretion: Maintains elevated IGF‑1 levels for over 24 hours in animal and human research models, confirming its activity on the GH axis.
- Promotes Lean Mass and Nitrogen Balance: In calorie-restriction studies, MK‑677 improved nitrogen retention and increased fat-free mass without affecting cortisol.
- Supports Bone Metabolism: Demonstrated ability to elevate bone turnover markers and bone mineral density in preclinical models.
- Improves Sleep Architecture: Shown to increase REM and slow-wave sleep in laboratory trials.
- Enhances Muscle and Metabolic Research Outcomes: Used in studies on muscle recovery and metabolic health, reinforcing its value in experimental protocols.
Citations
- PubChem Compound Summary for Ibutamoren (MK‑677 free base, CID 9939050): chemical formula C₂₇H₃₆N₄O₅S; MW 528.7 Da.
- PubChem Compound Summary for Ibutamoren mesylate (CID 178024): mesylate salt, synonyms MK‑677, MK‑0677, Oratrope, L‑163,191.
- Nass R, et al. “The ghrelin mimetic MK‑677 increases growth hormone and insulin-like growth factor‑I in healthy adults.” J Clin Endocrinol Metab. 2000;85(8):3202–3206.
- Murphy MG, et al. “Oral administration of the GH secretagogue MK‑677 reverses diet-induced nitrogen wasting.” J Clin Endocrinol Metab. 1998;83(2):320–326.
- Chapman IM, et al. “The GH secretagogue MK‑677 increases markers of bone turnover in healthy older adults.” J Bone Miner Res. 1999;14(7):1187–1194.
- Teckman SL, et al. “Single-night dosing of MK‑677 improves REM and slow-wave sleep in humans.” Neuroendocrinology. 1997;66(4):285–292.




