Evidence is limited to animal or in-vitro work. No human pharmacokinetics. Any human dose in circulation is extrapolated, and extrapolation across species routinely fails.
No published human half-life exists. The most-cited PK study was in rats and reports NO half-life value, only that systemic clearance is 5-fold lower than GHRP-6, that excretion is mainly urinary, and that intranasal bioavailability is ~20%. The commonly repeated "~2 hours" human figure could not be traced to any retrievable source.
No published human dose for GH purposes. Ipamorelin reached Phase 2 for postoperative ileus; dose levels are not reported in the registry summaries and the programme was discontinued. Circulating protocols (200-300 mcg) are community convention.
Human safety data exist only from discontinued Phase 2 trials and are not published in detail. Ipamorelin is described as selective for GH release without significant ACTH/cortisol or prolactin elevation, unlike GHRP-2 and GHRP-6, but that selectivity is established primarily in preclinical models. GH-class risks are theoretical here, not measured.