Description
MK-677 (Ibutamoren) is a synthetic non-peptide small molecule developed by Merck as an orally active growth hormone secretagogue. The compound is studied as a selective agonist of the ghrelin receptor (GHS-R1a), mimicking the action of endogenous ghrelin at the pituitary and hypothalamus to stimulate pulsatile growth hormone (GH) release. Unlike peptide-class GH secretagogues that require injection, MK-677 is orally bioavailable with a half-life of approximately 24 hours, supporting once-daily research protocols. Published preclinical and clinical research has examined the compound’s effects on GH and IGF-1 dynamics, body composition, bone mineral density, sleep architecture, and appetite regulation, with reported pharmacology that activates GH release without significantly affecting cortisol, prolactin, ACTH, or thyroid hormone levels.
Benefits (Research Focus)
• Studied as a selective ghrelin / GHS-R1a receptor agonist
• Investigated for pulsatile growth hormone (GH) release without exogenous GH administration
• Explored for downstream IGF-1 signaling and somatotropic axis activation
• Examined for body composition, lean mass, and adiposity endpoints in aged models
• Researched for bone mineral density, sleep architecture, and appetite regulation pathways
What Researchers Look At
• Plasma GH and IGF-1 dynamics following oral administration
• Pulsatile GH release patterns over 24-hour cycles
• Body composition endpoints (DEXA, fat mass, lean mass) in aged or sarcopenic models
• Cortisol, prolactin, ACTH, and aldosterone selectivity profiling
• Slow-wave sleep duration and REM sleep architecture in sleep research
Quick Specs
• Form: Gelatin capsule
• Strength: 10 mg / capsule
• Quantity: 30 capsules per bottle
• Excipient: Microcrystalline cellulose (MCC) — pharmaceutical-grade filler
• Purity: ≥99%
• Storage: Store in a cool, dry, dark place
Identity Basics
• Compound: MK-677 (Ibutamoren)
• Synonyms: Ibutamoren mesylate; MK-0677; L-163,191
• Class: Non-peptide ghrelin receptor (GHS-R1a) agonist; oral growth hormone secretagogue
• Chemical Formula: C₂₇H₃₆N₄O₅S (free base)
• Molecular Weight: 528.66 g/mol (free base); 624.77 g/mol (mesylate salt)
• CAS: 159634-47-6 (free base); 159752-10-0 (mesylate salt)
⚠️ Disclaimer
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This product is intended for laboratory research use only.
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Not for human or veterinary use.
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Not approved for diagnostic, therapeutic, or medical applications.
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Handle using appropriate laboratory safety procedures and personal protective equipment.
