Ipamorelin

Mechanism

Ipamorelin is a synthetic pentapeptide GH secretagogue that selectively activates the GHS-R1a receptor on anterior pituitary somatotrophs. Its distinguishing characteristic is exceptional selectivity: unlike GHRP-2 and GHRP-6, ipamorelin does not significantly stimulate ACTH-cortisol release or prolactin secretion at GH-stimulating doses. It also produces minimal appetite stimulation compared to other ghrelin-mimetic peptides. This selectivity is attributed to its unique receptor binding profile, which produces GH release in a dose-dependent manner without affecting other pituitary hormone axes. Ipamorelin preserves the pulsatile pattern of GH release.

What the literature has looked at

• Studies have investigated selective GH release without cortisol/prolactin elevation
• Research has examined its favorable side effect profile compared to other GHRPs
• Studies have explored synergistic GH release when combined with GHRH analogs
• Studies have assessed bone mineral density and body composition in research models

Research context, not a claim about what this compound does. Research Use Only — not for human or animal consumption. 21+.

Cited work

• Raun K, et al. Ipamorelin, the first selective growth hormone secretagogue. Eur J Endocrinol. 1998;139(5):552-561.

  Established ipamorelin as the first truly selective GH secretagogue, demonstrating dose-dependent GH release without significant changes in ACTH, cortisol, prolactin, FSH, LH, or TSH in both rats and dogs.

• Johansen PB, et al. Ipamorelin, a new growth-hormone-releasing peptide, induces longitudinal bone growth in rats. Growth Horm IGF Res. 1999;9(2):106-113.

  Ipamorelin stimulated longitudinal bone growth in rats with a potency comparable to GHRP-6 but with significantly fewer side effects on cortisol and prolactin.

Properties

type

Peptide (pentapeptide)