Ibutamoren vs Ipamorelin half-life
Ibutamoren has an elimination half-life of about 5 h; Ipamorelin has about 2 h. Ibutamoren (MK-677) is an orally active, non-peptide ghrelin-receptor agonist with a much longer half-life; ipamorelin is an injected peptide that clears within hours.
Side by side
| Ibutamoren | Ipamorelin | |
|---|---|---|
| Half-life | 5 h (range 4–6 h) | 2 h |
| Route | Oral daily | SC / IV |
| Category | GH secretagogues | GH secretagogues |
| Evidence | Limited | Limited |
| Remaining after 24 hours | 3.59% | 0.02% |
| Remaining after 7 days | <0.01% | <0.01% |
| ~97% cleared (5 half-lives) | 25 h | 10 h |
| Steady state (4-5 half-lives) | 20 h to 25 h | 8 h to 10 h |
Single-dose decay
Share of one dose remaining over time, assuming first-order elimination. Dashed lines mark each half-life.
Ibutamoren (t½ 5 h) Ipamorelin (t½ 2 h)
Ibutamoren: Non-peptide oral secretagogue; GH elevation outlasts plasma levels (~24 h). Ipamorelin: Human IV PK study: terminal half-life about 2 hours.
FAQ
Which lasts longer, Ibutamoren or Ipamorelin?
Ibutamoren lasts longer. Its half-life is about 5 h, versus 2 h for Ipamorelin, roughly 2.5 times longer.
How long do Ibutamoren and Ipamorelin stay in your system?
With first-order elimination, about 97% of a single dose is cleared after five half-lives: roughly 25 h for Ibutamoren and 10 h for Ipamorelin. Individual clearance varies.
How long until Ibutamoren and Ipamorelin reach steady state?
With consistent repeated dosing, levels approach steady state after 4 to 5 half-lives: about 20 h to 25 h for Ibutamoren, and 8 h to 10 h for Ipamorelin.
How reliable are these half-lives?
Ibutamoren: Limited evidence. Ipamorelin: Limited evidence. Anecdotal values are community estimates and may be far off.