From the FDA Drug Label
Contraception Use of MOUNJARO may reduce the efficacy of oral hormonal contraceptives. Advise patients using oral hormonal contraceptives to switch to a non-oral contraceptive method, or add a barrier method of contraception for 4 weeks after initiation and for 4 weeks after each dose escalation with MOUNJARO [see Drug Interactions (7.2), Use in Specific Populations (8. 3), and Clinical Pharmacology (12.3)].
Yes, oral contraceptives (OCs) may have reduced efficacy in patients taking Mounjaro (tirzepatide) 1. It is recommended that patients using oral hormonal contraceptives switch to a non-oral contraceptive method or add a barrier method of contraception for 4 weeks after initiation and for 4 weeks after each dose escalation with Mounjaro.
From the Research
Oral contraceptives may be less effective while taking Mounjaro (tirzepatide), and it is recommended to use an additional non-hormonal method of contraception, such as condoms or an IUD, to ensure effective birth control. This potential interaction is especially important during the first 2-4 weeks after starting Mounjaro or increasing the dose. The delayed stomach emptying caused by Mounjaro, a GLP-1/GIP receptor agonist, means that oral medications might stay in the stomach longer before reaching the intestines where they're absorbed, potentially reducing their effectiveness 2.
Key Considerations
- The risk of drug interaction with hormonal contraceptives should be anticipated as it may lead to unplanned pregnancies 2.
- Most interactions lead to a decrease in the effectiveness of hormonal contraceptives 2.
- If an enzyme inducer drug is started in a woman with hormonal contraception, it is recommended to use an additional mechanical contraception (barrier method) for the duration of the treatment and the cycle following its arrest 2.
- Optimal contraceptive selection requires patient and clinician discussion of the patient's tolerance for risk of pregnancy, menstrual bleeding changes, other risks, and personal values and preferences 3.
Recommendations
- Use an additional non-hormonal method of contraception, such as condoms or an IUD, when taking Mounjaro (tirzepatide) and oral contraceptives.
- Consult with a healthcare provider to determine the best approach to ensure effective contraception while continuing Mounjaro treatment.
- Be aware of the potential for reduced efficacy of oral contraceptives when taking Mounjaro, especially during the first 2-4 weeks after starting or increasing the dose.
Evidence Summary
The evidence suggests that drug interactions can reduce the effectiveness of hormonal contraceptives 2, 3, 4, 5. While there is no direct evidence on the interaction between Mounjaro and oral contraceptives, the mechanism of action of Mounjaro and the general principles of drug interactions with hormonal contraceptives support the recommendation to use an additional non-hormonal method of contraception. A study on contraception selection and effectiveness highlights the importance of considering individual factors and preferences when choosing a contraceptive method 3. Another study on pharmacokinetic drug interactions between oral contraceptives and second-generation anticonvulsants provides insight into the potential for drug interactions to affect contraceptive efficacy 4.