Library · Brain & nerves · Growth hormone secretion enhancement and muscle preservation
MK-677 (Ibutamoren)
Ibutamoren, MK-0677, L-163, 191, Oratrope
A non-peptide compound from the 1990s that mimics ghrelin to stimulate growth hormone and IGF-1 release through the pituitary's GHS-R receptor. Studied for lean mass, sleep, and bone density but never formally approved; still used as a research chemical.
Research score 65/100. Reference only, not a dose.
- Growth Hormone Release
- Muscle Growth
- Sleep Improvement
- Appetite Stimulation
- Recovery Enhancement
- Bone Health
- US status
- Research Chemical
- Approval
- Research Chemical Only
- Evidence
- Orally active GH secretagogue. Increases GH and IGF-1. Investigational for sarcopenia but failed to gain approval due to safety/efficacy balance.
- Research score
- 65 / 100
- Indication
- Research Only - No Medical Indication
- Origin
- USA
- Source category
- Brain & Nervous System
- Status group
- Research chemical
Mechanism
Binds GHS-R in the hypothalamus and pituitary, activating a G-protein pathway that raises calcium and PKC, amplifying GH pulses; its longer half-life than ghrelin gives sustained elevation over roughly a day.
Safety file
Raises risk of insulin resistance, high blood sugar, fluid retention, and increased appetite; carries an FDA heart-failure warning in some populations and is banned by WADA.
- Increased appetite
- Water retention
- Temporary insulin resistance
- Joint pain
- Numbness in hands
- Lethargy