GLP-1 drugs clear at very different speeds. Saxenda and Victoza (liraglutide) have a half-life of about 13 hours. Trulicity (dulaglutide) has about 5 days. Wegovy and Ozempic (semaglutide) have about 1 week. Those numbers decide how long a dose lasts, how forgiving a missed dose is, and how long effects can linger after you stop. This page lines them up using each FDA label.
| Drug (brand) | Half-life | Time to peak | Reaches blood | Dosing |
|---|---|---|---|---|
| Liraglutide (Saxenda, Victoza) | about 13 hours | Saxenda: 11 hours. Victoza: 8 to 12 hours | about 55% | Daily |
| Dulaglutide (Trulicity) | about 5 days | Median 48 hours (24 to 72) | 47% at 1.5 mg; 65% at 0.75 mg | Weekly |
| Semaglutide (Wegovy, Ozempic) | about 1 week | 1 to 3 days | 89% | Weekly |
Sources: Saxenda label, 12.3, Victoza label, 12.3, Trulicity label, 12.3, Wegovy label, 12.3 and Ozempic label, 12.3. "Reaches blood" is absolute bioavailability after an injection under the skin. The Trulicity peak is at steady state. For tirzepatide see our tirzepatide guide.
After each half-life, half of what was left is gone. After 5 half-lives about 3% remains, and most people treat the drug as cleared by then. This is a rule of thumb from basic pharmacology, not something the labels state, and people differ. Here is what it gives for each drug:
| Drug | 5 half-lives | Roughly |
|---|---|---|
| Liraglutide (13 hours) | 65 hours | About 3 days |
| Dulaglutide (5 days) | 25 days | About 3.5 weeks |
| Semaglutide (about 1 week) | 35 days | About 5 weeks |
For semaglutide the label itself speaks to this. The Wegovy label says that, with a half-life of about 1 week, semaglutide is in the bloodstream for about 5 to 7 weeks after the last injection of 2.4 mg (Wegovy label, 12.3). That is a little longer than the simple rule gives, so the label figure wins. Our deeper look at Ozempic's half-life has the full curve.
Liraglutide's half-life of about 13 hours is why it is injected every day. The Saxenda label says the highest blood level comes about 11 hours after the shot, and that absolute bioavailability is about 55%. It also says exposure was similar in the upper arm, abdomen and thigh (Saxenda label, 12.3).
Because a dose does not carry over for long, a gap matters sooner. The Saxenda label says that if more than 3 days have passed since the last dose, you should restart at 0.6 mg daily and work back up on the dose-increase schedule, to lower the risk of stomach side effects (Saxenda label, section 2). The patient leaflet says to call your provider if you miss 3 days or more. Do not double up to make up for a missed dose.
The Trulicity label gives an elimination half-life of about 5 days. At steady state the median time to peak is 48 hours, with a range of 24 to 72 hours. Steady state is reached between 2 and 4 weeks after starting weekly dosing, and the accumulation ratio is about 1.56, meaning the steady-state level is about one and a half times a single dose. The label also says the injection site (abdomen, upper arm or thigh) did not have a statistically significant effect on exposure (Trulicity label, 12.3).
Missed dose rule: give it as soon as you can if at least 3 days (72 hours) remain until the next scheduled dose. If less than 3 days remain, skip it (Trulicity label, 2.3).
Semaglutide peaks 1 to 3 days after an injection, and 89% reaches the blood (Wegovy label, 12.3). The missed-dose rules differ by product:
The Wegovy label also says to stop the drug at least 2 months before a planned pregnancy because of the long half-life (Wegovy label, 8.3). That is a good example of how a long tail shapes real planning.
Whatever you take, tell your care team about any planned procedure or sedation. The GLP-1 labels all note that these drugs slow stomach emptying.
Dose Track draws an estimated level curve from the doses you log, for daily and weekly GLP-1 drugs. You can see when a late dose created a dip and how the tail looks after a break. It also saves your injection sites so you can rotate them. See the GLP-1 tracking guide and our notes on injection site rotation.
This article is general information, not medical advice. Talk to your prescriber before you start, change or stop any medicine.