Bowers and colleagues established in the late 1980s and 1990s that synthetic GHRPs including GHRP-2 produce dose-dependent GH release in healthy adults that is synergistic with GHRH. Peak GH levels rise 3-10x with combined GHRP-2 + GHRH vs either alone. Cortisol and prolactin elevation is a real off-target — less than GHRP-6 but more than ipamorelin.
4 human studies · 6 animal studies
Synergistic GH release with GHRH — combined administration far exceeds additive (Bowers).
Peak GH 7-70 μg/L at doses of 0.1-1.0 μg/kg in healthy men.
Modest but real cortisol and prolactin co-stimulation.
Top citations
Bowers 1990 — GHRP/GHRH synergy
Bowers 1992 — Oral hexapeptide in humans
Our take
Real GH release, real cortisol bump. If you specifically want a GHRP without cortisol, ipamorelin is the cleaner pick.