MK-677 (Ibutamoren)

Structure: Non-peptide ghrelin mimetic — small molecule that binds the ghrelin (GHSR) receptor. Oral bioavailability distinguishes it from injectable GH peptides.

Dosage:

• Standard: 10-25mg/day oral
• Conservative (minimise glucose impact): 10-15mg/day
• Enhanced: 25mg/day (more GH release but worse glucose/insulin)

Administration:

• Oral capsule or liquid, once daily
• Take before bed — GH release during sleep, and hunger side effect is slept through
• Can be taken with or without food

Key Notes:

• Main advantage: oral dosing (no injections), long half-life (once daily), relatively inexpensive
• Main disadvantage: SIGNIFICANT impact on blood glucose and insulin sensitivity — this is the major concern
• Increased appetite can be extreme — counterproductive for cutting (some users gain unwanted fat)
• Fasting glucose and HbA1c can rise substantially, especially at 25mg/day
• Consider adding Metformin or Berberine to mitigate glucose impact
• Elevates prolactin mildly in some users — monitor if symptoms arise
• Water retention and bloating are common (similar to exogenous GH)
• Monitor: fasting glucose, HbA1c, IGF-1, fasting insulin, prolactin, lipid panel
• Not suppressive to HPTA — can be run year-round (but glucose impact may limit duration)