How long does Ipamorelin stay in your system?
Ipamorelin has a published half-life of approximately 2 hours (terminal). By the standard pharmacology rule of thumb, a drug is about 97% eliminated after roughly five half-lives, which here works out to about 10 hours. That was measured after a 15-minute intravenous infusion in healthy males.
Source: Gobburu et al., Pharm Res 1999 (PMID 10496658) · Peer-reviewed · measured: intravenous, 15-minute infusion · dataset reviewed September 23, 2026
What is the half-life of Ipamorelin?
Ipamorelin's terminal half-life of approximately 2 hours comes from a 1999 study in Pharmaceutical Research, measured in healthy males after a 15-minute intravenous infusion at five dose levels. Its pharmacokinetics were dose proportional, with a clearance of 0.078 L/h/kg.
Ipamorelin is a pentapeptide that activates the ghrelin receptor, GHS-R1a, and it is known for selectivity: in its original characterisation it released growth hormone without meaningfully raising cortisol, ACTH or prolactin. Its half-life sits well above GHRP-2's 0.55 hours, measured in children, and close to GHRP-6's 2.5 hour elimination phase.
How much Ipamorelin is left after each half-life?
Each half-life removes half of whatever is left, so the percentages are pure arithmetic and the same for any compound; only the clock changes. For Ipamorelin, one half-life is 2 hours. The rows below run that forward for a single amount with nothing added.
| Half-lives elapsed | Time elapsed | Remaining | Cleared |
|---|---|---|---|
| 1 | 2 hours | 50% | 50% |
| 2 | 4 hours | 25% | 75% |
| 3 | 6 hours | 12.5% | 87.5% |
| 4 | 8 hours | 6.25% | 93.75% |
| 5 | 10 hours | 3.13% | 96.88% |
| 6 | 12 hours | 1.56% | 98.44% |
| 7 | 14 hours | 0.78% | 99.22% |
Why do the numbers differ between sources?
Ipamorelin rests on a single intravenous human study. That makes the figure clean but narrow: it describes healthy males, an intravenous infusion and the dose levels tested. Our dataset holds no subcutaneous human figure, and absorption from an injection site can change the shape of the curve, as the growth hormone label shows.
Ipamorelin is not approved anywhere, so no label exists to cross-check the study. Any figure that differs substantially from approximately 2 hours should come with its own primary source.
What does a half-life not tell you?
The growth hormone pulse that ipamorelin triggers is a separate event from ipamorelin's own clearance, and IGF-1 downstream is separate again. A two hour half-life tells you about the peptide, not about the hormones it sets in motion.
It also says nothing about clinical benefit. The best human evidence, a placebo-controlled trial in bowel-resection patients, missed its primary endpoint. Ipamorelin is prohibited in sport by WADA, and detection is a matter of assay design, not half-life.
Can you run the numbers yourself?
The estimator applies the same decay arithmetic to any half-life, starting amount and time you enter. It opens with Ipamorelin's published value loaded. Type another figure to see how sensitive the result is to it.
Published value: Approximately 2 hours (terminal) (Intravenous, 15-minute infusion) · Gobburu et al., Pharm Res 1999 (PMID 10496658) · Compound profile
Show the math
What are the limits of this estimate?
Everything above is a single-compartment approximation: one pool of drug, falling by the same fraction in every interval. Real elimination varies with kidney and liver function, body composition, formulation and route, and a published figure describes only the route and the people it was measured in. Many compounds also show a fast distribution phase before the slower elimination the table describes.
A half-life is not a dosing schedule. Labelled intervals come from clinical trials that measured outcomes and tolerability, and nothing on this page suggests when to take, repeat or stop anything. Whether Ipamorelin is out of your system for drug-testing purposes is a different question again. Tests often look for metabolites rather than the parent compound, and the answer depends on the assay, its sensitivity and the sample type, none of which a plasma half-life captures.
FAQ.
Is ipamorelin's half-life longer than GHRP-2's?
On the published figures, yes. Ipamorelin's terminal half-life is approximately 2 hours in healthy males after intravenous infusion, while GHRP-2 was measured at 0.55 ± 0.14 hours in prepubertal children after an intravenous bolus. The populations and methods differ, so the comparison is approximate.
Was ipamorelin's half-life measured after injection under the skin?
No. It was measured after a 15-minute intravenous infusion. Absorption from a subcutaneous injection can change the shape of the concentration curve, and our dataset has no subcutaneous human figure for ipamorelin.
What does a clearance of 0.078 L/h/kg mean?
Clearance is the volume of plasma cleared of drug per hour, scaled to body weight. Together with how widely the drug distributes, it determines the half-life. The study reported dose-proportional pharmacokinetics across five dose levels, meaning exposure rose in step with dose.
For what the evidence on Ipamorelin actually shows, read the Ipamorelin profile. For approval and regulatory position, see is Ipamorelin legal. The half-life reference lists every sourced value side by side, including the compounds where a number circulates online with no reliable human data behind it.