Ipamorelin vs GHRP-2

Growth Hormone Axis

Growth Hormone Axis

Synthetic pentapeptide; growth hormone secretagogue

Synthetic hexapeptide; growth hormone secretagogue

Not FDA-approved; research use only

Not FDA-approved; approved as a diagnostic agent in some countries; research use only in the US

Ipamorelin acts on the growth hormone secretagogue receptor (the ghrelin receptor) in the pituitary and hypothalamus, prompting a pulse of growth hormone release.

GHRP-2 activates the growth hormone secretagogue (ghrelin) receptor, prompting the pituitary to release a pulse of growth hormone and acting synergistically with GHRH.

Evidence for ipamorelin is limited. Preclinical work and early pharmacology suggest it raises growth hormone with a relatively clean hormonal profile, but there are no published, well-controlled human trials demonstrating benefits for body composition, recovery, or other outcomes. Most marketed claims outpace the published data.

GHRP-2 has more human pharmacology behind it than many secretagogues, including use as a GH-stimulation test, and it reliably raises growth hormone. However, controlled trials supporting its marketed uses for muscle, recovery, or anti-aging are limited, and effects on appetite and other hormones complicate the picture.

Ipamorelin is often described as well-tolerated in short-term and animal studies, but human safety data is sparse. Long-term effects, interactions, and risks in people are unknown.

Short-term studies report it is generally tolerated, with increased appetite, flushing, and modest rises in cortisol and prolactin among the more common effects. Long-term human safety is not established.