Ipamorelin

What is ipamorelin?

Ipamorelin is a small pentapeptide that tells your pituitary to release its own growth hormone. It belongs to the growth-hormone-releasing-peptide (GHRP) family, and it earned a reputation as one of the "cleanest" of them: it prompts GH release without meaningfully raising cortisol or prolactin, which older GHRPs like GHRP-6 tend to do. It is a research compound, not an approved therapy, and it is most often discussed as half of a stack with CJC-1295.

How ipamorelin works

Ipamorelin is a selective agonist of the ghrelin receptor (GHS-R1a) in the pituitary. Ghrelin is best known as a hunger hormone, but the same receptor also drives growth-hormone release, and ipamorelin was designed to hit that GH lever specifically. The result is a short, pulsatile burst of GH that mimics the body's natural rhythm rather than a flat, artificial elevation. Because it works through a different receptor than the GHRH analogs, pairing it with one of those (like CJC-1295) stimulates GH through two complementary pathways at once.

What the research shows

Ipamorelin was first characterized in the late 1990s and was shown in early research to raise GH selectively, with far less effect on prolactin, ACTH, and cortisol than GHRP-6. That selectivity is its main claim to fame and is well supported at the mechanistic level. The honest limitation: it was explored pharmaceutically and then largely shelved, so there is no large modern trial base for the body-composition, recovery, and anti-aging uses it is marketed for today. The mechanism is solid; the outcome data for those specific uses is thin.

Dosage and how it is used

There is no approved dose. Community and clinic protocols commonly reference roughly 200 to 300 mcg subcutaneously, once to a few times per day, frequently timed before sleep and often combined with CJC-1295. These figures come from practice and early research rather than from modern dose-finding trials, so treat them as convention, not validated medicine.

→ How to reconstitute ipamorelin: calculator, units to draw & storage

Side effects and safety

Ipamorelin is generally considered one of the better-tolerated GHRPs, largely because of its selectivity, and short-term use tends to produce mild effects like water retention, head-rush sensations, or increased appetite. That said, it is not FDA-approved for anti-aging or body-composition use, and there is no long-term human safety data at the doses people actually use. As with any compound that raises GH and IGF-1, chronically elevated levels carry theoretical long-term concerns worth respecting.

• Research depth: well characterized mechanistically; limited modern outcome trials.
• Considered a "cleaner" GHRP, but no long-term human safety data at community doses.
• Not FDA-approved for these uses. Verify current legal and regulatory status independently.

Frequently asked questions

References

• Raun K et al. Ipamorelin, the first selective growth hormone secretagogue. European Journal of Endocrinology, 1998.
• Teichman SL et al. Prolonged stimulation of GH and IGF-1 secretion by CJC-1295 in healthy adults. J Clin Endocrinol Metab, 2006.