What it is
Ipamorelin is a pentapeptide ghrelin-receptor agonist that selectively stimulates GH release without significantly affecting cortisol, prolactin, or other pituitary hormones. By promoting natural GH pulses, it can support recovery from exercise and injury, lean body composition over time, and deeper sleep โ making it a popular choice in performance and wellness protocols for its clean profile.
Mechanism of action
Agonist at the growth hormone secretagogue receptor (GHSR-1a / ghrelin receptor) on pituitary and hypothalamic neurons. Unlike older secretagogues (GHRP-2, GHRP-6), ipamorelin has minimal appetite or cortisol effects.
Half-life: ~2 hours.
Evidence summary
The original Raun 1998 paper established its selectivity. Pharmacokinetic-pharmacodynamic and Phase 2 work has explored post-operative ileus and GH response in healthy volunteers. No long-term GH-replacement data available.
Typical dosing protocols
- 200โ300 mcg subcutaneous, 1โ3 times daily
- Best timed before bed (amplifies nocturnal GH pulse) or post-workout
- 12-week cycles, often stacked with CJC-1295
Side effects & safety
- Mild injection-site irritation
- Rare head-rush or transient tiredness
- Generally considered one of the cleanest GH secretagogues
Cited studies
- Raun K, Hansen BS, Johansen NL, et al. (1998). Ipamorelin, the first selective growth hormone secretagogue. European Journal of Endocrinology.PMID 9728535Read source โ
- (1999). Pharmacokinetic-Pharmacodynamic Modeling of Ipamorelin in Healthy Volunteers. Pharmaceutical Research.Read source โ
- (2014). Prospective, Randomized, Controlled Study of Ipamorelin for Post-Operative Ileus. International Journal of Colorectal Disease.Read source โ
All content is for research and educational purposes. Peptides described are sold for laboratory research use only and are not intended to diagnose, treat, cure, or prevent any disease. Always consult a qualified healthcare professional before beginning any protocol.