Ipamorelin
Reviewed by Fat Man in the Arena · Updated March 2026
Key Takeaway
Ipamorelin is a selective growth hormone secretagogue that stimulates the pituitary gland to release growth hormone. It is considered the mildest and most selective GHRP with fewer side effects than alternatives.
How it works
Selectively binds to the ghrelin/GHS receptor in the pituitary gland to stimulate natural growth hormone release in a pulsatile pattern. Unlike other GHRPs, it does not significantly increase cortisol or prolactin levels.
Benefits
- Increased growth hormone release
- Improved body composition (less fat, more lean mass)
- Better sleep quality
- Enhanced recovery from exercise
- Minimal side effects compared to other GH secretagogues
- Does not significantly raise cortisol or prolactin
Side effects
- Mild hunger increase (transient)
- Headache
- Water retention
- Tingling or numbness (rare)
Dosing protocol
Typical Dose
200-300 mcg per injection
Frequency
1-3 times daily, typically before bed
Cycle Length
8-12 weeks on, 4 weeks off
Best taken on an empty stomach. Often stacked with CJC-1295 for synergistic GH release. Not FDA-approved.
Key research
Ipamorelin, the first selective growth hormone secretagogue
European Journal of Endocrinology (1999) — PubMed
Ipamorelin demonstrated selective and potent GH release without affecting cortisol, ACTH, prolactin, or FSH/LH levels, making it the most selective GHRP studied.
Frequently asked questions
Ipamorelin is considered the safest GH secretagogue because it selectively stimulates growth hormone release without significantly raising cortisol, prolactin, or other hormones. A 1999 study in the European Journal of Endocrinology confirmed its selectivity compared to GHRP-2 and GHRP-6.
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Medical Disclaimer: This content is for informational and educational purposes only. It is not intended as medical advice or a substitute for professional medical consultation, diagnosis, or treatment. Always consult a qualified healthcare provider before starting any peptide protocol.