MK-677
aka Ibutamoren, Nutrobal
Oral GH secretagogue (ghrelin mimetic)
Half-life
~4–6 hours
How long it stays active in your body
Dosing
Nightly
How often you take a dose
Route
Oral
How it goes into the body
Status
Investigational
Still in clinical trials, not on the market
What it is
A non-peptide ghrelin receptor agonist taken orally. Increases endogenous GH and IGF-1 by mimicking ghrelin signaling at the pituitary. Multiple experts in our corpus warn against it — insulin resistance and water retention are common.
How it works
Binds GHSR1a (growth hormone secretagogue receptor) — the same receptor ghrelin activates. Triggers pituitary GH release. Side effect: also stimulates appetite and disrupts glucose homeostasis.
What the research says
Original Merck research for sarcopenia. Discontinued from clinical development. Multiple human trials show significant insulin resistance, water retention, and A1C elevation. Banned from compounding pharmacy use in 2023 (US).
Sources: PubMed: Ibutamoren
Common dosing ranges
- Range
- 12.5–25 mg/day oral (when used)
- Frequency
- Nightly
- Duration
- JD Denham: short cycles only, 35+ clients not actively cutting
Sources: PubMed
Administration
Side effects
Common
- Significant water retention
- Increased appetite (often debilitating)
- Lethargy
- Joint pain
Serious / theoretical
- Insulin resistance (pre-diabetic A1C in Tatem's self-trial)
- Elevated fasting glucose
- CHF concerns at chronic high doses
Sources: PubMed
Notes
Dr. Tatem, Dr. Jones DC, and Dr. Froese explicitly warn against MK-677. JD Denham uses cautiously in 35+ non-cutting clients. Banned from compounding 2023. Our take: hard pass for anyone with metabolic goals.