GHRP-2

GHRP-2 produces a stronger GH pulse at equivalent doses, but also elevates cortisol and prolactin. Ipamorelin is more selective and suitable for longer-term protocols where cortisol management matters. GHRP-2 is preferred when maximum GH pulse amplitude is the priority; Ipamorelin when clean hormonal profile matters more.

Cortisol elevation is dose-dependent. At 100 mcg, cortisol co-stimulation is minimal and transient. At 200–300 mcg, moderate elevation occurs. Above 300–500 mcg, clinically significant ACTH/cortisol increases are commonly observed. Most research protocols cap GHRP-2 at 100–200 mcg per injection to preserve the GH benefit while limiting cortisol load.

Yes — GHRP-2 combined with GHRH has been studied as a GH deficiency diagnostic tool (the GHRP-2 stimulation test). Research compared it favourably to the insulin tolerance test (ITT) for sensitivity and with fewer hypoglycaemia risks. It is not widely used clinically outside research endocrinology, but its diagnostic utility is well-established in the literature.

GHRP-2 stimulates appetite more strongly than Ipamorelin due to partial ghrelin pathway activation. This can be an advantage for researchers studying GH in contexts where anabolism and caloric intake are both goals. For protocols focused on body recomposition or fat loss, the appetite stimulation is typically an unwanted effect that Ipamorelin avoids.

GHRP-2 (branded Pralmorelin in Japan) is approved in Japan for GH deficiency diagnosis. Outside Japan it is used primarily as a research compound. Its pharmaceutical manufacturing in Japan has provided quality-controlled material for clinical studies that inform much of the available safety and pharmacokinetic data.