Does Zepbound Make Birth Control Less Effective?

Does Zepbound make birth control less effective? This is a critical question for patients prescribed tirzepatide for weight management. Zepbound (tirzepatide), an FDA-approved GLP-1 and GIP receptor agonist, can reduce the effectiveness of oral hormonal contraceptives by delaying gastric emptying. The FDA recommends using backup contraception for four weeks after starting Zepbound and after each dose increase. Non-oral methods—including IUDs, implants, injections, and vaginal rings—remain fully effective. Understanding this interaction is essential for preventing unintended pregnancy during treatment.

We offer compounded medications and Zepbound®. Compounded medications are prepared by licensed pharmacies and are not FDA-approved. References to Wegovy®, Ozempic®, Rybelsus®, Mounjaro®, or Saxenda®, or other GLP-1 brands, are informational only. Compounded and FDA-approved medications are not interchangeable.

Does Zepbound Affect Birth Control Effectiveness?

Zepbound (tirzepatide) is a glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) receptor agonist approved by the FDA for chronic weight management in adults with obesity or overweight with weight-related comorbidities. An important consideration for patients who could become pregnant is whether Zepbound affects contraceptive effectiveness.

According to the FDA-approved labeling, tirzepatide can reduce the effectiveness of oral hormonal contraceptives due to delayed gastric emptying. This is not merely theoretical—the FDA has documented reduced exposure to oral contraceptive components, particularly after initiation and dose escalation. The effect is most pronounced during the initial weeks of treatment and after dose increases.

Importantly, non-oral contraceptive methods—including intrauterine devices (IUDs), contraceptive implants, injections, vaginal rings, and most patches—are not expected to be affected by Zepbound. These methods deliver hormones directly into the bloodstream or act locally, bypassing the gastrointestinal tract entirely.

Patients should be informed that the FDA recommends using a non-oral contraceptive method or adding a barrier method (such as condoms) for 4 weeks after initiating Zepbound and for 4 weeks after each dose escalation. Additionally, if pregnancy occurs while taking Zepbound, the medication should be discontinued, as weight-loss medications are not recommended during pregnancy.

Drug Interactions Between Zepbound and Contraceptives

Understanding the pharmacokinetic profile of tirzepatide is essential when evaluating potential drug interactions with contraceptive agents. Tirzepatide is administered subcutaneously once weekly and has a half-life of approximately five days, allowing for steady-state concentrations that minimize fluctuations in drug levels. The medication is primarily eliminated through proteolytic degradation rather than hepatic metabolism, which reduces the likelihood of enzyme-mediated drug interactions.

The primary interaction concern relates to tirzepatide's effect on gastric emptying. By significantly delaying the rate at which stomach contents move into the small intestine—where most oral medication absorption occurs—Zepbound reduces the exposure to oral contraceptives. The FDA has documented this pharmacokinetic interaction, with the effect being greatest after the first dose and with dose increases.

This interaction is particularly important for combination oral contraceptives and progestin-only pills. Progestin-only pills require especially strict timing and consistent absorption to maintain contraceptive efficacy, making them particularly vulnerable to absorption delays. For patients taking oral medications with a narrow therapeutic index, monitoring or considering alternative formulations may be necessary.

Non-oral contraceptive methods bypass the gastrointestinal tract and are not affected by delayed gastric emptying. However, it's worth noting that some contraceptive patches may have reduced effectiveness in patients with a BMI ≥30 kg/m² or higher body weight, independent of any interaction with Zepbound. For patients with obesity, long-acting reversible contraceptives (LARCs), injections, or vaginal rings may be preferable options.

What the FDA Says About Zepbound and Birth Control

The FDA-approved prescribing information for Zepbound provides specific guidance regarding the use of oral contraceptives in patients taking tirzepatide. According to the official label, tirzepatide delays gastric emptying and reduces exposure to oral contraceptives, with the effect being most pronounced after the first dose and after dose escalations.

The FDA label explicitly recommends that for patients taking oral contraceptives, an alternative contraceptive method or an additional barrier method should be considered for four weeks after initiation of Zepbound and for four weeks after each dose escalation. This recommendation is based on observed pharmacokinetic interactions showing reduced oral contraceptive exposure, not merely theoretical concerns.

The four-week timeframe allows the body to adapt to the medication and for gastrointestinal effects to stabilize. While the gastric-emptying effect is largest after initiation and after each dose escalation, it tends to diminish over time as the body adjusts to the medication.

It is important to note that clinical trials of tirzepatide did not specifically evaluate contraceptive efficacy as a primary or secondary endpoint, so the true clinical impact remains incompletely characterized. Healthcare providers should review the current FDA prescribing information when counseling patients, as recommendations may be updated as additional post-marketing data become available. The FDA's guidance emphasizes shared decision-making, encouraging clinicians to discuss contraceptive options with patients and to individualize recommendations based on patient preferences, medical history, and the specific contraceptive method being used.

Contraception Recommendations While Taking Zepbound

For patients initiating Zepbound therapy, a comprehensive discussion about contraception is an essential component of pre-treatment counseling. Clinicians should assess the patient's current contraceptive method, reproductive plans, and risk factors for unintended pregnancy. This conversation should occur before starting tirzepatide and be revisited at each dose escalation.

For patients using oral contraceptives, the following recommendations should be considered:

• Backup contraception: Use an additional barrier method (such as condoms) for at least four weeks after starting Zepbound and after each dose increase, per FDA guidance.

• Timing considerations: Take oral contraceptives at a consistent time each day, preferably when gastrointestinal symptoms are minimal.

• Missed doses or GI illness: Follow CDC Selected Practice Recommendations for missed pills. If vomiting occurs within 2 hours of taking an oral contraceptive or if severe diarrhea lasts more than 24 hours, consider this a missed pill and follow appropriate guidance for your pill type.

• Alternative methods: Consider switching to a non-oral contraceptive method if concerned about absorption issues or if experiencing significant gastrointestinal side effects.

Preferred contraceptive options during Zepbound treatment include methods that are not affected by gastrointestinal absorption:

• Long-acting reversible contraceptives (LARCs): Intrauterine devices (hormonal or copper) and contraceptive implants offer highly effective, absorption-independent contraception.

• Injectable contraceptives: Depot medroxyprogesterone acetate provides three months of protection per injection.

• Transdermal and vaginal methods: Contraceptive patches and vaginal rings deliver hormones systemically without relying on gastrointestinal absorption. Note that some patches may have reduced effectiveness in patients with a BMI ≥30 kg/m².

If emergency contraception is needed, a copper IUD is the most effective option and is unaffected by BMI or gastrointestinal absorption. For oral emergency contraception, ulipristal acetate is generally more effective than levonorgestrel, especially at higher BMI. If vomiting occurs within 3 hours of taking oral emergency contraception, the dose should be repeated.

Patients should be counseled to discontinue Zepbound immediately if pregnancy occurs, as weight-loss medications are not recommended during pregnancy. Regular pregnancy testing should be considered if there is any concern about contraceptive failure while taking Zepbound.

Frequently Asked Questions