MK-677 (Ibutamoren)
Research chemical — not an approved drug or dietary supplement
This compound is sold for research and is not FDA-approved for human use or as a dietary supplement. Human evidence is limited; purity and dosing of consumer products are unverified. The data below is an evidence review for education only — talk to a clinician before considering it.
At a glance
- Best for
- Not established — investigational
- Main caution
- Unapproved GH secretagogue; raises IGF-1 with risks to glucose tolerance and unknown long-term safety, often sold illegally as a 'supplement'
What is it
MK-677 (ibutamoren) is an orally active, non-peptide growth-hormone secretagogue that mimics ghrelin to stimulate the pituitary to release growth hormone and raise IGF-1. It was investigated pharmaceutically (including for conditions such as frailty and growth hormone deficiency) but was never FDA-approved, and development for marketed indications was discontinued. It is widely sold as a 'research chemical' and misrepresented as a dietary supplement (which it is not — the FDA has warned that ibutamoren is not a lawful dietary ingredient). Human data exist from clinical trials, but long-term safety is not established and it is prohibited in sport.
Is it worth it for you?
Probably skip if…
- You expect an approved drug or a legal dietary supplement — it is neither (FDA has flagged it as not a lawful dietary ingredient)
- You would source it from 'research chemical' vendors with no purity, dosing, or quality oversight
- You are not prepared for known effects like raised blood glucose/insulin resistance and water retention
- You are not prepared for unknown long-term safety of chronically elevated GH/IGF-1
- You compete in sport — ibutamoren is prohibited under WADA rules
Safety
Common side effects
Reported in trials: increased appetite, water retention/edema, transient fatigue or lethargy, joint/muscle aching, and increases in fasting blood glucose
Serious risks
- Impaired glucose tolerance / insulin resistance and raised blood sugar
- Unregulated purity and dosing of research-grade product (and mislabeled 'supplements')
- Unknown long-term effects of sustained GH/IGF-1 elevation, including theoretical risk of promoting existing tumors; one heart-failure trial in elderly patients was halted over a safety signal
- No clinical monitoring of glucose, IGF-1, or cardiac status when self-administered
Who should avoid it
- Anyone using it without direct medical supervision
- Pregnancy and breastfeeding
- People with diabetes, prediabetes, or impaired glucose tolerance
- People with heart failure or significant cardiovascular disease
- People with cancer or a history of cancer
- Competitive athletes subject to anti-doping rules
Pregnancy & breastfeeding
Avoid — no safety data.
Choosing a product
Be skeptical of
- 'Proven' muscle-building, fat-loss, or anti-aging claims
- Marketing it as a legal dietary supplement or 'natural' GH booster
- Vendors selling 'for research use only' product for human consumption
Track MK-677 (Ibutamoren) with Pilora
Set up dose reminders, check interactions, and join the community in the Pilora iPhone app.
Coming to App StoreDisclaimer: This compound is not approved by the FDA for human use and is not a dietary supplement. This page is an educational review of available research — much of it preclinical or early-stage — not a recommendation to use it. Consumer product quality is unregulated. Consult a qualified clinician.