Mounjaro and contraception: What you need to know

If you’re thinking about starting Mounjaro or are already using it for weight loss, you might be concerned about interactions with other medicines, especially if you are taking contraceptives. You might be wondering, “Can Mounjaro make it harder to manage family planning?” or “Can Mounjaro make my oral contraception less effective?” Here’s everything you need to know, including how to buy Mounjaro, what Mounjaro is, and how it could affect your birth control.

Key takeaways

• Mounjaro can reduce the effectiveness of oral contraceptives:
  Mounjaro slows down how quickly your stomach empties, which makes it harder for your body to absorb oral contraceptive pills. This can make the medication less effective at preventing pregnancy.
• Non-oral contraceptives are not affected by Mounjaro:
  Birth control methods like patches, rings, injections, IUDs, IUS, and condoms work in ways that don’t rely on your digestive system, so they remain effective when used with Mounjaro.
• If you use oral contraceptives, you should also use a barrier method:
  It’s strongly recommended to use condoms or another barrier method for at least four weeks after starting Mounjaro or after each dose increase, as the pill alone may not be reliable.
• Not all weight loss injections impact contraception:
  Other injectable weight loss medications, such as Wegovy (semaglutide) and Saxenda (liraglutide), do not interfere with how oral contraceptives work.
• Consider your options and talk to a healthcare professional:
  If you’re taking Mounjaro and need reliable contraception, non-oral methods may be more convenient and practical. Always consult with your pharmacist or doctor to determine the best option for your specific needs.

What is Mounjaro?

Mounjaro (active ingredient: tirzepatide) is a new injectable medication used for weight loss. It works by mimicking the effects of two natural hormones in your body—GLP-1 and GIP.

GLP-1 and GIP are natural hormones released by your gut when you eat.

They help your body release insulin (which lowers blood sugar) only when you need it, and they also reduce the amount of another hormone called glucagon (which raises blood sugar).

GLP-1 also helps you feel full by slowing down how quickly your stomach empties and by reducing your appetite. GIP helps your body use nutrients and energy from your food more effectively [1].

In summary, Mounjaro induces weight loss by slowing stomach emptying and regulating appetite, resulting in a feeling of fullness, reduced hunger, and fewer food cravings [2].

How does Mounjaro affect oral contraception?

Because Mounjaro slows down stomach emptying, it can impact how your body absorbs medicines taken by mouth, including the contraceptive pill.

After starting Mounjaro or increasing your dose, your body may not absorb the pill as well, making it less effective at preventing pregnancy [3].

Why can Mounjaro affect how well contraceptive pills work?

Mounjaro it slows down how quickly your stomach empties food into your intestines—a process called “delayed gastric emptying” [4].

Because Mounjaro slows down your digestion, it can also slow down how quickly your body absorbs medicines taken by mouth, including birth control pills.

This means the contraceptive pill might not be absorbed as well, especially when you first start Mounjaro or when your dose is increased.

If the pill isn’t absorbed properly, it may not work as effectively at preventing pregnancy.

What is the clinical trial evidence behind Mounjaro’s effect on the contraceptive pill?

A clinical study found that when women took the contraceptive pill (containing ethinyl oestradiol and norgestimate) with a single dose of Mounjaro (tirzepatide 5 mg), the peak amount of the pill absorbed into the body dropped by 55% to 66% [5].

Overall exposure to the pill in the body was also reduced by 16% to 23%, and it took 2.5 to 4.5 hours longer for the pill to start working [5].

These changes happen because Mounjaro slows down how quickly your stomach empties, which can delay and reduce how much of the pill gets absorbed.

What does this mean for you?

If you’re taking the contraceptive pill and start Mounjaro, or if your Mounjaro dose increases, the pill might not work as well to prevent pregnancy.

To stay protected, you should either switch to a non-pill form of contraception (like a patch, injection, or implant) or use an extra barrier method (like condoms) for 4 weeks after starting Mounjaro and for 4 weeks after each time your dose goes up.

In summary:

Mounjaro can reduce how much of the contraceptive pill your body absorbs by up to 66%, making it less effective. Always use extra protection for 4 weeks after starting or increasing your Mounjaro dose.

Do other weight loss injections interfere with contraception?

Most weight loss injections, like Ozempic (semaglutide), Saxenda (liraglutide), and Wegovy (semaglutide), belong to a group of medicines called GLP-1 receptor agonists.

These medicines work by helping you feel fuller for longer and slowing down the rate at which your stomach empties food. Because they slow digestion, you might wonder if they also affect how your body absorbs the contraceptive pill.

What does the research say?

Studies have looked at whether these common weight loss injections interfere with how well the contraceptive pill works.

The good news is that for GLP-1 medications like semaglutide, liraglutide, dulaglutide, and exenatide, there is no significant effect on the absorption or effectiveness of the pill [6].

That’s why there are no special warnings or recommendations to use extra contraception with these medicines.

What does the research say about  Mounjaro (tirzepatide)?

Mounjaro is a newer type of injection that works slightly differently because it acts on two hormones (GLP-1 and GIP) and causes a more pronounced delay in stomach emptying, especially when starting and with each dose increase.

With Mounjaro, studies have shown it can reduce how much of the contraceptive pill gets absorbed by up to 20% and can delay how long it takes to start working  [5].

Because of this, it’s recommended to use an extra form of contraception (like condoms) for 4 weeks after starting Mounjaro or after each dose increase.

In summary:

• Most weight loss injections (like Ozempic, Saxenda, Wegovy) do not interfere with the contraceptive pill.
• Mounjaro (tirzepatide) can interfere with the pill, so you should use extra protection for 4 weeks after starting or increasing the dose.

If you’re unsure which medicine you’re on or need personalised advice, please contact us.

What should you do if you’re taking Mounjaro and contraception?

• If you use the pill, use an extra method of contraception, like condoms, for at least four weeks after starting Mounjaro or after each dose increase.
• Consider switching to a non-oral contraceptive (like a patch, injection, IUD, or ring), as these are not affected by Mounjaro.
• Always talk to your pharmacist or doctor for personalised advice.

Key points to remember

• Mounjaro can make oral contraceptives less effective by slowing their absorption.
• Manufacturer guidelines say to use backup contraception for four weeks after starting or increasing your Mounjaro dose.
• Other GLP-1 medications (like semaglutide) do not have this effect on birth control pills.
• Non-oral contraceptives are not affected by Mounjaro.

If you want to buy Mounjaro online or have questions about Mounjaro and contraception, our team at Courier Pharmacy is here to help.

We offer expert advice and support to keep you safe and informed about your medicines.

Mounjaro and contraception FAQs

Can I use oral contraception while taking Mounjaro?

You don’t have to stop using the pill, but it’s essential to know that Mounjaro can reduce the effectiveness of oral contraceptives.

Experts recommend using an extra barrier method, like condoms, for four weeks after starting Mounjaro and for four weeks after every dose increase.

For many people, this means you may need to use condoms throughout your Mounjaro treatment.

Should I use a different type of contraception with Mounjaro?

Yes, it’s a good idea to consider non-oral contraceptives while using Mounjaro.

Methods such as the contraceptive patch, injection, ring, IUD (coil), or IUS are not affected by how your stomach digests medicine. These options work directly through the skin, bloodstream, or uterus, so Mounjaro doesn’t impact their effectiveness. Please refer to the table below:

What if I want to get pregnant?

If you’re planning a pregnancy, you should stop using Mounjaro before trying to conceive.

The effects of Mounjaro on pregnancy and unborn babies haven’t been studied, so your pharmacist or doctor will likely advise you to delay treatment until after pregnancy and breastfeeding.

How to get Mounjaro from Courier Pharmacy

1.      Complete the online questionnaire

Start by filling out our secure online medical questionnaire. This helps our pharmacists and prescribers assess your suitability for Mounjaro and ensure it’s safe for you.

2.      Upload a photo

You’ll need to upload a clear, recent photo of yourself for identity verification and safe prescribing.

3.      Provide evidence of dose titration (if requesting a higher dose)

If you’re purchasing a higher dose of Mounjaro, you must provide proof (such as a prescription history, photos of previous pens or documentation) that you have safely titrated up to the requested dose.

4.      Provide your GP details

Enter your GP’s contact information so we can keep your doctor informed about your Mounjaro treatment, supporting your ongoing care and safety.

5.      Attend a follow-up video call

To comply with the latest regulations, you will need to complete a follow-up video consultation with our clinical team. This ensures you’re using Mounjaro safely and allows us to answer any questions you may have.

Why buy Mounjaro from Courier Pharmacy?

• Competitive prices
  Get Mounjaro at some of the best prices available online, making your treatment more affordable.
• Free sharps bin supplied
  We provide a complimentary sharps bin with your order for safe and easy disposal of used injection pens.
• Free needles supplied
  All necessary needles for your treatment are included at no extra cost.
• Free alcohol wipes supplied
  Stay safe and hygienic—alcohol wipes are included free with every order.
• All consultations are free
  Enjoy free medical consultations with our experienced team, from your initial assessment to ongoing support.
• Medicines available to manage side effects
  If you experience side effects that become too severe, we can supply additional medications to help you manage them and stay comfortable during your treatment.

Courier Pharmacy is committed to providing a safe, affordable, and supportive experience for all our patients. If you have any questions or need further assistance, our friendly team is here to help every step of the way.

Our Courier Pharmacy team created this content to provide general information and is not a substitute for professional medical advice. For personalised recommendations about your health, always consult with your doctor or healthcare provider.

References

1. Syed, Y.Y., 2022. Tirzepatide: first approval. Drugs, 82(11), pp.1213-1220.
2. Courier Pharmacy, 2024. Can you drink alcohol while taking Mounjaro? How does Mounjaro cause weight loss? [online] Courier Pharmacy. Available at: https://courierpharmacy.co.uk/can-you-drink-alcohol-while-taking-mounjaro-2/#h-how-does-mounjaro-cause-weight-loss [Accessed 17 Jun. 2025].
3. Skelley, J.W., Swearengin, K., York, A.L. and Glover, L.H., 2024. The impact of tirzepatide and glucagon-like peptide 1 receptor agonists on oral hormonal contraception. Journal of the American Pharmacists Association, 64(1), pp.204-211.
4. Courier Pharmacy. (n.d.) The Mounjaro Fifth Dose. Available at: https://courierpharmacy.co.uk/the-mounjaro-fifth-dose-2/ (Accessed: 18 June 2025).
5. Eli Lilly. (n.d.) MOUNJARO: Product monograph including patient medication information. Eli Lilly Canada Inc.
6. Maideen, N.M.P., 2019. Pharmacologically relevant drug interactions of glucagon-like peptide-1 receptor agonists. J Anal Pharm Res, 8(2), pp.51-3.