Muscle & Growth Hormone
GHRP-6
growth hormone-releasing hexapeptide
What it is
GHRP-6 is the original GH-releasing peptide, developed by Cyril Bowers in the 1980s. It's most known for its strong appetite-stimulating effect — it's the GHRP that hits ghrelin (the hunger hormone) hardest. Useful for hard gainers who struggle to eat enough.
How it works
Activates ghrelin receptors in the pituitary AND in the hypothalamus, producing both GH release and an aggressive appetite signal. The strongest "munchies" of any GHRP.
Benefits
- Significant appetite increase (intentional benefit for bulking)
- Strong GH release
- Improved sleep
- Lean mass and recovery support
Timeline
- 30–60 min post-injection
- Hunger hits hard.
- Week 1–2
- Improved sleep, increased food intake.
- Week 6–8
- Lean mass gains; cycle off.
Dosing & titration
Standard dose100–200 mcg, 1–3x daily
Cycle length8–12 weeks on, 4 weeks off
TimingEmpty stomach, paired with a GHRH
When to titrate upMost users do well at 100–200 mcg. Higher doses produce more cortisol/prolactin issues.
Side effects & risks
- Aggressive hunger (intentional but can derail cuts)
- Cortisol & prolactin elevation
- Water retention
- Tingling, head-rush after injection
Don't use during a cut. The appetite stimulation is too strong. Use Ipamorelin instead if cutting.
Typical price
$50–$80/mo5 mg vial from a 503A compounding pharmacy.
Studies
- Bowers CY et al. On the in vitro and in vivo activity of a new synthetic hexapeptide that acts on the pituitary to specifically release growth hormone — The original GHRP-6 paper. PubMedEndocrinology, 1984
- Search PubMed for GHRP-6 — PubMed searchLive PubMed search
Educational reference only. Not medical advice.