Is MK-677 (Ibutamoren) safe?
Well-StudiedSide effects, risks, and safety considerations based on available research.
Research status
MK-677 (Ibutamoren) has a relatively strong evidence base including clinical trials in humans. This does not mean it is without risks, but its safety profile is better characterized than many other peptides.
Known concerns & side effects
- ⚠significantly increases appetite — can lead to unwanted weight gain
- ⚠raises fasting blood glucose and may reduce insulin sensitivity
- ⚠two-year study in elderly showed no improvement in functional outcomes despite increased GH/IGF-1
- ⚠may cause water retention, joint pain, and numbness/tingling
- ⚠long-term elevated IGF-1 is associated with increased cancer risk in epidemiological studies
- ⚠not FDA approved for any indication
- ⚠often sold through unregulated SARMs vendors with quality concerns
Use caution with
See all 2 studies on the full MK-677 (Ibutamoren) profile.
Frequently asked questions
Is MK-677 a SARM?
No. MK-677 is a growth hormone secretagogue, not a selective androgen receptor modulator. It does not interact with androgen receptors. It is often sold alongside SARMs by the same vendors, which has created this common misconception.
Does MK-677 actually build muscle?
MK-677 raises GH and IGF-1 levels, which are involved in muscle growth. However, the largest clinical trial (2-year study in elderly) showed no significant improvement in strength or functional capacity despite sustained hormonal elevation. The muscle-building claims outpace the clinical evidence.
Why was MK-677 never approved?
Despite extensive clinical study, MK-677 failed to demonstrate sufficient clinical benefit relative to its side effects. The increases in blood glucose and insulin resistance were particularly concerning, and the two-year study showed elevated GH markers did not translate to meaningful functional improvements.
Full MK-677 (Ibutamoren) Profile
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Last updated: 2025-04-09
Medical Disclaimer
The information on this site is for educational and informational purposes only. It is not intended as medical advice and should not be used to diagnose, treat, or prevent any condition. Always consult with a qualified healthcare professional before starting any new supplement, peptide, or treatment protocol.