SARMs & Related Compounds
MK-677
Ibutamoren · Growth Hormone Secretagogue
What it is
MK-677 (Ibutamoren) is a growth hormone secretagogue that increases endogenous GH and IGF-1 levels via ghrelin receptor agonism. It's NOT a SARM — it doesn't bind androgen receptors. Instead, it mimics ghrelin, signaling the pituitary to increase GH secretion. Made it through Phase 2 trials for muscle wasting and bone density.
How it works
Ghrelin receptor agonist that stimulates GH release from the anterior pituitary in a pulsatile manner (mimicking natural secretion). Also increases appetite via central ghrelin signaling. GH rises in a dose-dependent, sustained manner over 6–12 weeks.
Benefits
- Increased GH and IGF-1 (measured via blood work)
- Muscle gain + recovery (secondary to GH rise)
- Improved sleep quality (GH-dependent)
- Potential bone density gains
- Appetite increase (not always a benefit)
Timeline
- Week 1–2
- Appetite increase; better sleep onset.
- Week 4–6
- GH elevation measurable; strength/recovery gains.
- Week 8–12
- Peak GH levels; sustained muscle gains.
Dosing & titration
Standard dose10–25 mg orally daily
Cycle length12–16 weeks continuous (no off-cycle needed)
When to titrate upStart at 10 mg for 2 weeks, assess appetite/sleep, titrate to 15–25 mg.
TimingUsually dosed once daily, typically in the evening for sleep quality.
Side effects & risks
- Increased appetite (can lead to fat gain if not controlled)
- Insulin resistance / blood sugar elevation (dose-dependent)
- Lethargy initially (GH-related)
- Joint pain (water retention related to GH)
- Carpal tunnel risk (GH-related)
- Potential prolactin elevation (minor)
Monitor blood glucose and insulin. Get fasting glucose and HOMA-IR before, during (8 weeks), and after cycle. Appetite control essential or will gain excess fat. Not androgen suppressive — PCT not required. No major drug interactions.
Typical price
$40–$80/moResearch suppliers. Relatively affordable; widely available.
Studies
- Svensson J et al. The growth hormone secretagogue ibutamoren (MK-677) increases serum insulin-like growth factor-1 in health and disease — Phase 2 efficacy. PubMedSearch PubMed for MK-677 ibutamoren
- Search PubMed for MK-677 / ibutamoren — PubMed searchLive PubMed search
Educational reference only. Not medical advice. Not FDA-approved.