Semaglutide vs Retatrutide half-life
Semaglutide has an elimination half-life of about 6.9 days; Retatrutide has about 6 days. Semaglutide targets the GLP-1 receptor alone, while investigational retatrutide targets GIP, GLP-1 and glucagon receptors. Both are long-acting, weekly compounds.
Side by side
| Semaglutide | Retatrutide | |
|---|---|---|
| Half-life | 6.9 days (range 6–7 days) | 6 days (range 5.6–6.9 days) |
| Route | SC weekly / oral daily | SC weekly |
| Category | GLP-1 & incretins | GLP-1 & incretins |
| Evidence | Clinical | Limited |
| Remaining after 24 hours | 90.4% | 89.1% |
| Remaining after 7 days | 49.4% | 44.5% |
| ~97% cleared (5 half-lives) | 34.4 days | 30 days |
| Steady state (4-5 half-lives) | 27.5 days to 34.4 days | 24 days to 30 days |
Single-dose decay
Share of one dose remaining over time, assuming first-order elimination. Dashed lines mark each half-life.
Semaglutide (t½ 6.9 days) Retatrutide (t½ 6 days)
Semaglutide: FDA label: elimination half-life of about 1 week. Retatrutide: Phase 1/2 trials: about 6 days.
FAQ
Which lasts longer, Semaglutide or Retatrutide?
Semaglutide and Retatrutide have similar half-lives: about 6.9 days and 6 days.
How long do Semaglutide and Retatrutide stay in your system?
With first-order elimination, about 97% of a single dose is cleared after five half-lives: roughly 34.4 days for Semaglutide and 30 days for Retatrutide. Individual clearance varies.
How long until Semaglutide and Retatrutide reach steady state?
With consistent repeated dosing, levels approach steady state after 4 to 5 half-lives: about 27.5 days to 34.4 days for Semaglutide, and 24 days to 30 days for Retatrutide.
How reliable are these half-lives?
Semaglutide: Clinical evidence. Retatrutide: Limited evidence. Anecdotal values are community estimates and may be far off.