Study wrapper · #223
Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers.
Editor's note
This is the closest thing ipamorelin has to a foundational human study, and it is worth weighting accordingly. In a dose-escalation trial, 40 healthy men (eight per dose across five infusion rates) received ipamorelin while researchers tracked drug and GH levels. Pharmacokinetics were dose-proportional with a short ~2-hour half-life, and each dose produced a single, self-limiting pulse of GH peaking around 40 minutes and then declining to negligible levels. The team fitted an indirect-response PK/PD model, estimating a half-maximal stimulating concentration of 214 nmol/L and a maximal GH production rate. Importantly, this establishes that ipamorelin raises GH in humans and characterises how, but it is a short-term pharmacology study in healthy young men, not a test of any body-composition, recovery, or clinical endpoint, and the GH response varied substantially between individuals. For Ipamorelin, regard this as solid human PK/PD groundwork, not evidence of therapeutic benefit.
Plain-language abstract
This trial measured what ipamorelin does in the human body. Forty healthy men were split into five groups of eight, and each group received a different infusion dose of ipamorelin over 15 minutes. Researchers then measured both the drug's levels and the growth hormone it triggered. The drug behaved predictably: higher doses produced proportionally higher blood levels, it cleared quickly with a half-life of about two hours, and every dose caused a single burst of growth hormone that peaked at roughly 40 minutes and then fell back to very low levels. Using these data, the researchers built a mathematical model describing the relationship between drug concentration and growth-hormone release, estimating the concentration needed for a half-maximal response. The growth-hormone response varied more from person to person than the drug's handling did. The study set out to describe ipamorelin's pharmacology across a range of doses, and did so; it did not test effects on body composition, strength, or any health outcome. No adverse events were described in the abstract.