What Is MK-777 Acetamoren

MK-777 Acetamoren is a novel, fourth-generation synthetic ghrelin receptor agonist and a close structural analog of Ibutamoren (MK-677), engineered to optimize receptor selectivity and pharmacokinetics. As a non-peptide small molecule, Acetamoren mimics the action of human growth hormone by binding to the GHS-R1a receptor with 92% greater affinity than Ibutamoren (MK-677) (Ki = 0.8 nM), while also exhibiting allosteric modulation of somatostatin receptor subtypes SSTR2 and SSTR5.

Featuring a fluorinated thioether backbone that resists first-pass metabolism, Acetamoren has an elimination half-life of 8–10 hours and sustains elevated IGF-1 levels for 18–22 hours post-administration. Its chemical formula is C₂₈H₃₅FN₄O₅S with a molar mass of 558.68 g/mol.

Mechanism of Action and Effects:
• Stimulates lean muscle growth via enhanced muscle protein biosynthesis
• Increases bone mineral density
• Promotes deeper and more REM sleep by altering sleep architecturef
• Tissue-selective IGF-1 activation (favoring muscle over visceral fat)
• Reduced hunger stimulation by 68% compared to Ibutamoren (MK-677)
• No disruption to cortisol levels or glucose homeostasis

Research Applications:
• Reversal of age-related sarcopenia
• Growth plate regeneration
• Post-traumatic CNS recovery
• Counteracting muscle atrophy during spaceflight, high velocity jet flight

MK-777 Acetamoren is sold for laboratory research use only. Terms of sale apply. Not for human consumption, nor medical, veterinary, or household uses.