Starting A GLP-1? What It Means For Birth Control And Pregnancy Plans
If you could get pregnant, there are two questions worth asking before you start a GLP-1 weight loss medication: does it change how my birth control works, and what happens if I want to get pregnant? The FDA labels for the brand-name versions answer both, and the answers differ a little between semaglutide and tirzepatide.
Why Tirzepatide Comes With A Birth Control Note
Tirzepatide (the active ingredient in Mounjaro and Zepbound) slows how quickly your stomach empties. Its labeling says this can make birth control pills less effective. The label's advice: if you take an oral hormonal contraceptive, switch to a non-oral method, or add a barrier method like condoms, for 4 weeks after you start and for 4 weeks after each dose increase. Non-oral methods such as an IUD, implant, patch, ring, or shot are not affected in the same way.
What Semaglutide's Label Says
Semaglutide (the active ingredient in Ozempic and Wegovy) also slows stomach emptying, but its labeling does not carry the same switch-or-back-up advice for the pill. One practical point applies to either medication: nausea, vomiting, and diarrhea are common early on, and the CDC's contraception recommendations treat significant vomiting or diarrhea as a reason the pill may not be fully absorbed. If that happens, ask your provider whether you need a back-up method.
If You Are Planning A Pregnancy
These medications are not for use during pregnancy. The labels say weight loss offers no benefit during pregnancy and may cause harm to the fetus, and to stop the medication when pregnancy is recognized. Because semaglutide stays in the body for a long time, the Wegovy label goes further and says to stop at least 2 months before a planned pregnancy. If pregnancy is anywhere on your horizon, say so at your visit so your provider can plan the timing with you.
The Safety Rules That Apply To Everyone
Both medications carry a boxed warning about thyroid C-cell tumors seen in rodent studies, and neither should be used if you or a family member has had medullary thyroid cancer, or if you have multiple endocrine neoplasia type 2 (MEN 2). The labels also warn about pancreatitis and gallbladder problems. For what is normal in the first weeks and what is not, see our guide to GLP-1 side effects.
The semaglutide and tirzepatide offered through Urania are compounded. Compounded medications are not FDA-approved and have not been evaluated by the FDA for safety or effectiveness. The label guidance above comes from the brand-name products with the same active ingredients, and your provider applies it to the medication you are prescribed.
Where To Start
Tell your provider which birth control you use and whether you might want to get pregnant in the next year. A licensed provider reviews your history and decides whether a GLP-1 fits, which one, and at what dose. If you are still choosing between the two, our semaglutide vs. tirzepatide guide walks through how they differ.
This guide explains general information and is not medical advice. It doesn't replace a licensed provider reviewing your own history.