How Long Does Saxenda Stay in Your System?

Saxenda's elimination half-life is 13 hours, per the FDA label: that is how long it takes for the amount of liraglutide in your body to halve. Levels peak 11 hours after a dose, and on the label schedule (a daily injection) they reach steady state about 3 days after the first dose. After a last dose they fall below 5% of that steady level in about 3 days.

Between scheduled doses, levels swing between a peak and a trough of about 61% of that peak, which is why the chart looks like a sawtooth rather than a flat line. The label also reports that approximately 55% of each dose is absorbed into circulation; the chart's mg figures build that in.

The Saxenda label says to resume the once-daily schedule with the next dose after a miss, never doubling up; if more than 3 days have elapsed since the last dose, it instructs reinitiating at 0.6 mg to reduce gastrointestinal symptoms.

That window is the half-life doing the work: with 13 hours of half-life, a late dose still lands on a meaningful base. This is the label's instruction to prescribers, not our advice; if you have missed a dose, your own label and prescriber are the authority.

Saxenda's label has the strictest gap rule of any GLP-1 here: after more than 3 days without a dose, it instructs restarting at the lowest 0.6 mg step. The calculator shows why: with a 13-hour half-life, three days is more than five half-lives, so the liraglutide is essentially gone and your gastrointestinal tolerance resets with it.

The weekly injections never face this because their gaps are measured against half-lives of five to seven days. It is the clearest example on this site of a missed-dose rule being the half-life story in miniature.