Saxenda and Hormonal Contraceptives: What the Drug Interaction Evidence Actually Shows

What the Saxenda label says

The current Saxenda label (effective 2026-02-25) says Saxenda delays gastric emptying and so has the potential to affect absorption of oral medicines [1]. It also says that in clinical pharmacology trials liraglutide did not affect absorption of the tested oral medicines to a clinically relevant degree, and it advises monitoring for possible consequences of delayed absorption [1].

Birth control is not singled out in that section for a dose change, a method switch, or backup contraception [1]. A combined pill label addresses a different kind of interaction. The Sprintec label says to counsel backup contraception when enzyme inducers such as rifampicin, carbamazepine, phenytoin or St. John's wort are used, and to continue it for 28 days after the inducer is stopped [2].

The oral contraceptive study

The Saxenda label reports a study with an oral contraceptive containing 0.03 mg ethinyl estradiol and 0.15 mg levonorgestrel [1]. Liraglutide lowered ethinyl estradiol Cmax by 12% and levonorgestrel Cmax by 13% [1]. Ethinyl estradiol AUC was unchanged, levonorgestrel AUC rose 18%, and Tmax was delayed by 1.5 hours [1].

What the study does and does not show

These are pharmacokinetic results: the label reports hormone concentrations, not pregnancy rates [1]. The study does not show a fall in total ethinyl estradiol exposure [1]. Combined oral contraceptives lower pregnancy risk mainly by suppressing ovulation [2], and the label does not report how these small peak changes affect ovulation or pregnancy risk [1]. The label does not state that oral contraceptives are less effective with Saxenda [1].

Pregnancy wording in the current label

The current Saxenda label does not list pregnancy as a contraindication [1]. It says Saxenda should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus, that weight loss offers no benefit to a pregnant patient, and that Saxenda should be discontinued when pregnancy is recognized [1]. An earlier Saxenda label version listed pregnancy as a contraindication [3].