Ipamorelin dosage in the research record — by species, by route, with the half-life that frames it

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This page describes the ipamorelin doses used in published studies — in rats, swine, ferrets, and one set of human volunteers. It is a research summary, not an instruction. Nothing here tells anyone how much to use, because there is no approved human dose: ipamorelin has never been approved as a medicine. Doses are given the way the studies gave them — as an amount per kilogram of body weight, by a stated route (into a vein, under the skin, and so on). The one number that travels across all of it is the half-life — about two hours in people — because how fast the body clears a dose shapes how the dose was designed ^[2]. Read the doses below as a record of what researchers did, not as a protocol.

Doses used in human studies

Two human datasets exist, and both used the intravenous route. The pharmacokinetic study gave healthy male volunteers five 15-minute intravenous infusions ranging from 4.21 to 140.45 nmol/kg, as single doses, to map the kinetics — the source of the ~2-hour half-life, 0.078 L/h/kg clearance, and 0.22 L/kg volume of distribution ^[2].

The Phase 2 postoperative-ileus trial used a fixed regimen: 0.03 mg/kg intravenously twice daily, on postoperative days 1 through 7 or until discharge, in 114 bowel-resection patients. The trial missed its primary endpoint (time to first tolerated meal 25.3 vs 32.6 hours, p=0.15), and treatment-emergent adverse events occurred in 87.5% of the ipamorelin arm versus 94.8% of placebo — no ipamorelin-specific safety signal in that short perioperative window ^[3]. These are the only human dosing figures in the literature, and both are intravenous and clinic-administered.

Doses used in animal studies, by route

Rodent and large-animal studies dominate the dose record. In rats, the bone-growth study used subcutaneous ipamorelin at 18, 90, and 450 micrograms per day, divided three times daily for 15 days ^[4]. The 2024 ferret cachexia study used intraperitoneal ipamorelin at 1-3 mg/kg ^[9]. The founding swine and rat characterization established the GH ED50 at 2.3 nmol/kg in swine by the intravenous route ^[1].

Routes studied include intravenous (human PK and clinical trials; rodent efficacy), subcutaneous (rodent bone and body-composition work, and the dominant route in community use), intranasal (rodent PK, roughly 20% bioavailability), and intraperitoneal (rodent and ferret efficacy). Oral delivery applies only to engineered ipamorelin-derived analogs, not to ipamorelin itself, which is not orally bioavailable ^[8].

How the half-life shapes the dosing picture

A roughly 2-hour terminal half-life and a single GH pulse that peaks near 40 minutes ^[2] explain the shape of the studied regimens: short, repeated intravenous dosing in the human trial (twice daily) ^[3] and divided daily dosing in the rat bone study (three times daily) ^[4], rather than a single sustained exposure. A short half-life means the compound is cleared between doses and the GH response is pulsatile rather than continuous.

This is also why community 'stack' protocols pairing ipamorelin with CJC-1295 are explicitly outside the evidence base. Those subcutaneous regimens have no peer-reviewed human dosing basis, were never tested as a combination in any trial, and are described here as anecdotal, not recommended ^[3].

Handling and stability (research-supply context)

Ipamorelin is supplied as a lyophilized (freeze-dried) powder, as either the free base or the acetate salt, and reconstituted with bacteriostatic water for research handling. As a peptide it is degraded by heat and by repeated freeze-thaw cycles, and reconstituted solution is typically kept refrigerated. These are general peptide-handling observations from the research-supply literature, not a clinical preparation instruction, and they carry no dosing implication.