Ipamorelin vs GHRP-2
A comparison of Ipamorelin and GHRP-2 as growth hormone secretagogues, including selectivity, side effect profiles, half-life, and research protocol context.
A comparison of Ipamorelin and GHRP-2 as growth hormone secretagogues, including selectivity, side effect profiles, half-life, and research protocol context.
Overview
Ipamorelin and GHRP-2 are both ghrelin receptor agonists studied for pulsatile growth hormone release, but they are consistently distinguished by selectivity profile. Ipamorelin is generally characterized as a more selective secretagogue with a narrower side-effect window, while GHRP-2 is associated with broader receptor activity and more pronounced ancillary effects.
Mechanism Comparison
Both compounds act on the ghrelin receptor (GHSR-1a), but GHRP-2 is associated with stronger cortisol and prolactin stimulation alongside GH release. Ipamorelin is specifically noted in the research literature for its comparative selectivity — it stimulates GH release with minimal impact on cortisol, prolactin, or ACTH, which is a key distinction in protocol planning discussions.
Dosing and Protocol Comparison
Both compounds are typically studied at similar frequency intervals, and both are often compared in the context of pairing with a GHRH analog such as CJC-1295. The choice between them in protocol literature often comes down to tolerability preference and whether the research question requires a cleaner secretagogue signal or accepts the broader hormonal effects associated with GHRP-2.
Evidence Comparison
Ipamorelin has attracted more attention in selective secretagogue protocol discussions, while GHRP-2 has a somewhat longer research history in earlier GH-stimulation studies. Both compounds remain primarily in the preclinical to limited human study range. For research purposes, the selectivity difference is generally the more useful comparison axis than simple evidence volume.