Ibutamoren (MK-677)

Reliably raises GH and IGF-1 levels with oral dosing. Clinical benefits for body composition and function are modest and accompanied by notable side effects including increased appetite and insulin resistance.

A rough internal score reflecting quantity, quality, and consistency of human evidence. Not a clinical recommendation.

Multiple trials in elderly subjects show sustained increases in GH and IGF-1 over months. Some trials report modest lean mass gains and improved sleep quality. However, fasting glucose and insulin resistance consistently worsen. A 2-year trial in elderly adults did not demonstrate functional benefits despite hormonal changes.

• Reliable oral GH and IGF-1 elevation
• May improve sleep quality and REM duration
• Modest lean mass gains in some trials
• Convenient oral dosing unlike GH peptides

Clinical trials used 25 mg once daily, typically in the evening.

• Increased appetite
• Water retention
• Insulin resistance
• Elevated fasting glucose
• Lethargy

Worsens insulin sensitivity. May elevate fasting glucose. Not FDA-approved. Contraindicated in diabetes or pre-diabetes. Cancer risk from chronically elevated IGF-1 is a theoretical concern.

Raising GH/IGF-1 levels does not automatically translate to clinical benefit. The 2-year elderly trial is a key cautionary result.

• Sleep55
• Muscle50
• Recovery45
• Longevity25