GLP-1 and birth control pills: do they interact?
GLP-1 weight-loss shots slow your stomach, so people worry their daily birth control pill will not absorb. The good news: most labels say the pill still works fine, with one important catch for tirzepatide.
You take a GLP-1 shot each week to lose weight. You also take a birth control pill each day. A worry pops up. Will the shot stop the pill from working? It is a smart question. Let us look at what the medicine labels actually say.
Why people worry: the slow stomach
GLP-1 shots slow down your stomach. Food and pills sit inside longer before moving on. Doctors call this 'delayed gastric emptying'. That just means the stomach empties slower. If a pill sits too long, your body might soak up less of it. That is the worry with birth control pills. The Wegovy label says it plainly. It warns the shot 'has the potential to impact the absorption of concomitantly administered oral medications'. So the worry makes sense. But 'can' is not 'will'. The labels tested this for real with the pill.
What each label says about the pill
GLP-1 shots make birth control pills stop working.
mostly falseMostly false for semaglutide and liraglutide — but it depends for tirzepatide. The Wegovy, Ozempic and Saxenda labels tested the pill and found no clinically meaningful drop in pill levels. The Mounjaro and Zepbound labels found a real drop at the first dose, so they say to add a barrier method (like a condom) for 4 weeks after starting and after each dose increase. The stomach-slowing effect is biggest at the start and shrinks over time.
What to do if you take both
The bottom line
Most GLP-1 labels say the birth control pill still works fine, with no extra steps needed. The big exception is tirzepatide (Mounjaro and Zepbound). Their labels say add a barrier method for 4 weeks after starting and after each dose increase. When in doubt, ask your doctor. Do not change your pill on your own.