MK-677 (Ibutamoren)

MK-677 (Ibutamoren) is a long-acting, orally active ghrelin mimetic that stimulates the secretion of growth hormone (GH) and insulin-like growth factor 1 (IGF-1) by binding to the GHS-R1a receptor. It has been studied in preclinical and clinical research for its potential to support GH/IGF-1 axis signaling, muscle mass retention, and metabolic regulation in aging and disease models.

• Acts as a ghrelin receptor (GHS-R1a) agonist
• Stimulates pulsatile growth hormone release
• Increases circulating IGF-1 without elevating cortisol or prolactin significantly
• Promotes sleep-related GH secretion and deep wave sleep

• unit: mg

  low dose: 10

  frequency: Once daily, typically in the evening

  high dose: 30

  standard dose: 20

  administration route: Oral

• Take once daily for 8–12 weeks. Breaks of 2–4 weeks recommended to monitor insulin sensitivity. Best taken pre-sleep or fasted in AM.

common: ["Water retention","Increased appetite","Mild lethargy or fatigue"]

warnings: ["Can exacerbate insulin resistance and cause transient blood sugar elevation","Use caution in diabetics or those with metabolic syndrome"]

long term: ["Long-term use may affect insulin sensitivity; monitoring is advised"]

sequence: Non-peptide mimetic (ghrelin receptor agonist)

half life: 24 hours

degradation: Metabolized in liver; maintains stable GH elevation throughout day

molecular weight: 528.7

molecular formula: C27H36N4O5S

tissue specificity: Acts on pituitary GH axis, hypothalamus, and metabolic tissues

• MK-677, an orally active growth hormone secretagogue, reverses diet-induced catabolism.clinicalPMID 9467534 ↗
• The Safety and Efficacy of Growth Hormone Secretagogues.reviewPMID 28400207 ↗