Insulin glargine vs Insulin degludec half-life
Insulin glargine has an elimination half-life of about 12 h; Insulin degludec has about 25 h. Both are long-acting basal insulins. Degludec forms chains of hexamers under the skin that dissolve slowly, giving it a longer half-life and flatter profile than glargine.
Side by side
| Insulin glargine | Insulin degludec | |
|---|---|---|
| Half-life | 12 h (range 12–19 h) | 25 h |
| Route | SC daily | SC daily |
| Category | Insulins | Insulins |
| Evidence | Clinical | Clinical |
| Remaining after 24 hours | 25% | 51.4% |
| Remaining after 7 days | <0.01% | 0.95% |
| ~97% cleared (5 half-lives) | 2.5 days | 5.2 days |
| Steady state (4-5 half-lives) | 2 days to 2.5 days | 4.2 days to 5.2 days |
Single-dose decay
Share of one dose remaining over time, assuming first-order elimination. Dashed lines mark each half-life.
Insulin glargine (t½ 12 h) Insulin degludec (t½ 25 h)
Insulin glargine: Absorption-limited; flat profile lasting about 24 hours. Insulin degludec: FDA label: about 25 hours.
FAQ
Which lasts longer, Insulin glargine or Insulin degludec?
Insulin degludec lasts longer. Its half-life is about 25 h, versus 12 h for Insulin glargine, roughly 2.1 times longer.
How long do Insulin glargine and Insulin degludec stay in your system?
With first-order elimination, about 97% of a single dose is cleared after five half-lives: roughly 2.5 days for Insulin glargine and 5.2 days for Insulin degludec. Individual clearance varies.
How long until Insulin glargine and Insulin degludec reach steady state?
With consistent repeated dosing, levels approach steady state after 4 to 5 half-lives: about 2 days to 2.5 days for Insulin glargine, and 4.2 days to 5.2 days for Insulin degludec.
How reliable are these half-lives?
Insulin glargine: Clinical evidence. Insulin degludec: Clinical evidence. Anecdotal values are community estimates and may be far off.