Incretin-based medicines
GLP-1 half-life comparison
Last reviewed 2026-11-08 · Sources cited for every value
At a glance
FDA-approved
Liraglutide
- 13 hoursVictoza
- 13 hoursSaxenda
FDA-approved
Dulaglutide
- 5 daysTrulicity
Overlay and compare
Idealized elimination curves
Each curve is the same mathematical model drawn from each compound's reported half-life. These are not measured comparative concentrations: routes, formulations, populations and absorption differ, and none of this ranks one compound above another.
- Semaglutide
- Tirzepatide
- Dulaglutide
- Liraglutide
- Retatrutide
Show chart data as a table
| Series | 1× t½ | 2× t½ | 3× t½ | 4× t½ | 5× t½ |
|---|---|---|---|---|---|
| Semaglutide | 7 days · 50% | 14 days · 25% | 21 days · 12.5% | 28 days · 6.25% | 35 days · 3.125% |
| Tirzepatide | 5 days · 50% | 10 days · 25% | 15 days · 12.5% | 20 days · 6.25% | 25 days · 3.125% |
| Dulaglutide | 5 days · 50% | 10 days · 25% | 15 days · 12.5% | 20 days · 6.25% | 25 days · 3.125% |
| Liraglutide | 0.542 days · 50% | 1.08 days · 25% | 1.63 days · 12.5% | 2.17 days · 6.25% | 2.71 days · 3.125% |
| Retatrutide | 6 days · 50% | 12 days · 25% | 18 days · 12.5% | 24 days · 6.25% | 30 days · 3.125% |
| Compound | Reported half-life | Estimate | Measure | Population | Route · form | Evidence | Status | Limitations |
|---|---|---|---|---|---|---|---|---|
| SemaglutideResearch profile ↗ | 1 week | Elimination half-life | Adults with type 2 diabetes (clearance about 0.05 L/h stated for this population) | Subcutaneous · Solution for injection (pen) | High | FDA-approved | Steady state reported after 4–5 weeks of once-weekly administration; absolute bioavailability 89 %. | |
| TirzepatideResearch profile ↗ | 5 days | Elimination half-life | Healthy subjects and adults with type 2 diabetes (the label states PK is similar between them) | Subcutaneous · Solution for injection (single-dose pen, vial, KwikPen) | High | FDA-approved | Steady state is reported after 4 weeks of once-weekly administration; mean absolute bioavailability 80 %. | |
| DulaglutideResearch profile ↗ | 5 days | Trulicity | Elimination half-life | Healthy subjects and adults with type 2 diabetes (the label states PK is similar between them) | Subcutaneous · Solution for injection (single-dose pen) | High | FDA-approved | Steady state between 2 and 4 weeks (accumulation ratio about 1.56); median steady-state Tmax 48 h. |
| LiraglutideResearch profile ↗ | 13 hours | Elimination half-life | Not specified in the half-life statement | Subcutaneous · Solution for injection (pen) | High | FDA-approved | Cmax at 8–12 h; absolute bioavailability about 55 %. Generic liraglutide labels carry the same section 12.3 text. | |
| RetatrutideResearch profile ↗ | 6 days | Urva S et al | Elimination half-life | Adults aged 20–70 with type 2 diabetes (52 received retatrutide, 72 enrolled) | Subcutaneous · Investigational solution for injection | Moderate | Investigational | Value read from the published abstract; the abstract gives no range or variability and does not describe the PK method. A healthy-volunteer single-dose study (Coskun et al., Cell Metab 2022) reports PK that "supported once-weekly" use without a number in its abstract, so it is not shown. |
Why the half-lives differ
Albumin binding
Semaglutide (C18 diacid), tirzepatide (C20 diacid) and retatrutide carry fatty side chains that bind albumin and slow clearance. Liraglutide's C16 fatty acid binds less strongly.
Fc fusion
Dulaglutide fuses GLP-1 analogue chains to an IgG4 Fc fragment. The large protein is absorbed and cleared slowly by a different mechanism.
Product and population
Labels report values for their own populations and products. Tirzepatide's two labels differ slightly for that reason, and oral and injected semaglutide share a half-life but not an absorption profile.
Limitations
The curve is an idealized first-order elimination model. It is a mathematical illustration of what a half-life means, not a medical prediction. It does not model:
- Patient-specific pharmacokinetics
- Drug absorption from the site of administration
- Multi-compartment distribution
- Active metabolites
- Receptor occupancy
- How long a clinical effect lasts
- Individual blood concentrations
- Drug interactions
- Changes in kidney or liver function
Frequently asked questions
Which GLP-1 medicine has the longest half-life?
Among the compounds here, semaglutide’s labels report about 1 week, retatrutide’s phase 1b study about 6 days, and tirzepatide and dulaglutide about 5 days. Liraglutide is about 13 hours. A longer half-life does not make a medicine better or safer.
Why is liraglutide’s half-life so much shorter?
Liraglutide uses a C16 fatty acid that binds albumin less tightly than the C18 and C20 diacids of semaglutide and tirzepatide, so it clears faster, which is why it is a once-daily product.
Are all of these approved?
Semaglutide, tirzepatide, liraglutide and dulaglutide are FDA-approved in specific products. Retatrutide is investigational and not approved anywhere as of the review date.
Can I compare the curves directly?
Only loosely. Each curve applies the same idealized model to each reported value, but the values come from different populations, analyses and products, and absorption is not modelled.