Does Mounjaro affect fertility?

If you're taking Mounjaro or considering it as part of your weight loss journey, you might be wondering whether it could affect your chances of getting pregnant. Whether you're hoping to start a family or simply want to understand how the medication might affect your reproductive health, it's important to separate fact from fiction.

While there's currently insufficient evidence that Mounjaro directly increases or decreases fertility, changes in weight and metabolic health can influence reproductive health. For some people, losing weight may help improve hormonal balance and ovulation, potentially increasing their chances of becoming pregnant.

In this guide, we'll explore what the evidence tells us about Mounjaro and fertility, explain the important considerations around contraception and pregnancy, and help you understand what to do if you're planning to start a family.

Can Mounjaro affect fertility?

There's currently limited evidence that Mounjaro directly affects fertility. However, the weight loss associated with treatment may influence reproductive health, particularly in people whose weight or underlying health conditions affect their menstrual cycle.

It's important to distinguish between the medication itself and the changes happening in your body during treatment. While Mounjaro isn't a fertility treatment, improvements in weight and metabolic health may indirectly affect your chances of becoming pregnant. That’s because excess body weight can disrupt hormone levels and ovulation, making it more difficult to conceive. For some people, losing weight may help improve these processes, although the effects vary depending on individual circumstances.

Can Mounjaro make you more fertile?

Mounjaro isn't designed to improve fertility, and there's currently insufficient evidence that the medication directly increases your chances of conceiving.

However, weight loss may improve fertility for some people, particularly those with polycystic ovary syndrome (PCOS). Research suggests that GLP-1 receptor agonists can improve menstrual regularity in women with PCOS, potentially helping to restore more regular ovulation.

It's worth remembering that these findings primarily relate to other GLP-1 medications, rather than Mounjaro specifically. Improvements in fertility aren't guaranteed, and Mounjaro shouldn't be used as a fertility treatment.

Can Mounjaro cause infertility?

There's currently no established evidence that Mounjaro causes infertility in humans. However, research into its long-term effects on reproductive health remains limited.

Changes to your menstrual cycle during weight loss don't necessarily indicate a fertility problem. Significant weight changes, stress, and conditions such as PCOS can all affect menstrual regularity.

If you've noticed changes to your cycle, our guide to whether Mounjaro can stop periods explores the possible reasons and when to seek medical advice.

If you're concerned about your fertility, speak to your healthcare provider for personalised advice.

Can weight loss affect fertility?

Yes, weight loss can affect fertility, although the impact will depend on your individual health and circumstances.

Excess body weight can affect hormone levels, menstrual regularity, and ovulation, potentially making it more difficult to become pregnant. For people living with overweight or obesity, losing weight may help improve hormonal balance and support more regular ovulation.

However, losing weight doesn't always improve fertility. Rapid weight loss or not eating enough can also disrupt your menstrual cycle, sometimes causing periods to become irregular or stop altogether.

The aim is to make gradual, sustainable changes that support your overall health rather than focusing on weight loss alone. If you're planning a pregnancy, speak to your healthcare provider about the safest approach to managing your weight and preparing for conception.

Can you get pregnant on Mounjaro?

Yes, you can get pregnant while taking Mounjaro. The medication isn't a form of contraception and shouldn't be relied upon to prevent pregnancy.

If weight loss helps improve previously irregular ovulation, your chances of conceiving may change during treatment. This makes it important to consider contraception, even if you've previously experienced difficulties becoming pregnant.

The European Medicines Agency recommends using contraception while taking Mounjaro. Although the medication can affect how quickly oral contraceptives are absorbed, current European prescribing guidance doesn't consider this effect clinically significant and doesn't require changes to oral contraception.

If you're sexually active and don't want to become pregnant, speak to your healthcare provider about suitable contraception throughout your treatment.

What happens if I get pregnant while on Mounjaro?

If you discover you're pregnant while taking Mounjaro, stop using the medication and contact your healthcare provider as soon as possible.

Mounjaro isn't recommended during pregnancy because there's limited information about its effects on developing babies. However, taking Mounjaro before realising you're pregnant doesn't automatically mean your pregnancy has been harmed.

Your healthcare provider can review your treatment, discuss any potential risks, and help you understand the next steps. If you're taking Mounjaro to manage type 2 diabetes, they'll also help you find a suitable alternative to keep your blood sugar levels under control.

Mounjaro and congenital conditions: what do we know?

There's currently insufficient evidence to establish whether Mounjaro increases the risk of congenital conditions, sometimes called “birth defects”, in humans.

Animal studies have identified potential risks to foetal development, but it's unclear whether these findings apply to human pregnancies. Research involving pregnant people is still limited, so the safety of Mounjaro during pregnancy hasn't been established.

This uncertainty is why healthcare professionals recommend avoiding Mounjaro during pregnancy. If you've been exposed to the medication while pregnant, your healthcare provider can discuss what this means for you and whether any additional monitoring is appropriate.

What if I'm planning to get pregnant?

If you're planning to start a family, it's important to discuss your treatment with your healthcare provider before trying to conceive.

European prescribing guidance recommends stopping Mounjaro at least one month before a planned pregnancy. This allows time for the medication to leave your system.

Your healthcare provider can help you plan when to stop treatment and discuss how to manage your weight or blood sugar levels safely before pregnancy.

If you're hoping to conceive in the near future, having this conversation early can help you prepare with confidence.

“It's understandable to have questions about fertility when you're taking Mounjaro, especially if you're thinking about starting a family. While losing weight may improve fertility for some people, it's important to remember that Mounjaro isn't recommended during pregnancy. If you're planning to conceive, speak to your healthcare team so you can make a plan that's right for you.”

Ayesha BashirPrescribing Pharmacist

Getting support throughout your treatment

Whether you're concerned about how Mounjaro might affect your fertility or you're planning to start a family, it's important to have access to reliable advice throughout your treatment.

At myBMI, our treatment plans include ongoing clinical support to help you manage your weight loss safely and sustainably. Our clinical team can answer questions about your medication, discuss potential side effects, and help you make informed decisions about your treatment. We also offer free medication to help manage certain side effects, if deemed appropriate.

For more information about what to expect during treatment, explore our guide to Mounjaro side effects.

Whatever your plans for the future, having the right support can help you feel confident about your health and the decisions you make along the way.

Sources

• Impact of obesity on infertility in women. (2015) Journal of the Turkish German Gynecological Association. [Accessed 11 October 2026]
• Effects of GLP1RAs on pregnancy rate and menstrual cyclicity in women with polycystic ovary syndrome: a meta-analysis and systematic review. (2023) BMC Endocrine Disorders. [Accessed 11 October 2026]
• Missed or late periods. (2026) NHS. [Accessed 11 October 2026]
• Mounjaro - Product Information. (2026) European Medicines Agency. [Accessed 11 October 2026]