What it is

Peptides acting on it

Evidence

  • [anecdote-bb] Ghrelin (stomach, on hunger) enhances GHRH’s effect and drives a GH pulse — but the effect collapses when somatostatin is high (e.g. after eating). Arginine 5–10 g (with ornithine/lysine) blunts somatostatin, partly rescuing a GHRP dose taken on a full stomach. Hunger is the expected side effect. — Vigorous Steve

  • [educational] GHRP receptor is especially prone to desensitization → use a GHRP (e.g. ipamorelin) with a GHRH for synergy, not alone; ipamorelin’s selectivity minimises prolactin/cortisol off-effects. — GH admin guide

  • [educational] GHRP monotherapy can’t sustain IGF-1 (GHSR-1A rapidly desensitizes + chronic GHRP raises somatostatin; hexarelin 16-wk study, restored after 4-wk break). Selectivity ranks: ipamorelin (highest) > GHRP-2/hexarelin > GHRP-6 > ghrelin. — GH selection guide