Expert Answers to 4 FAQs About Weight-Loss Drugs and Fertility

Weight-loss medications are more popular than ever. Oral options, such as Qsymia (phentermine / topiramate ER) and Contrave (naltrexone / bupropion), have been around for a while. And the newer injectable weight-loss medications, such as Wegovy (semaglutide) and Zepbound (tirzepatide), seem to have several additional benefits beyond just losing weight.

But what do we know about weight-loss drugs and fertility? Whether you’re looking to improve your fertility or hoping to avoid an “Ozempic baby,” here’s what we know so far.

1. Can weight-loss medications affect your fertility?

It’s possible for weight-loss medications to affect your fertility. Many lifestyle factors can contribute to female infertility. Some of the most common include:

• Older age 

• A body mass index (BMI) that’s considered overweight or obese (25 and higher)

• Smoking

• Drinking alcohol often or in large amounts

• Missed periods due to intense emotional or physical stress

Studies show that making lifestyle changes (including diet, exercise, or medication) that lead to weight loss may improve fertility in women with a BMI of 25 and higher. This is because a high body weight can interfere with your hormone levels, which can impact your menstrual cycle and how your eggs mature and are released. Weight loss can help bring your hormones back into balance, which may help increase your chances of becoming pregnant.

But research is mixed when it comes to weight loss and fertility. The current evidence suggests that women with a BMI of 25 and over who aren’t ovulating may experience the most benefit from weight loss. But weight loss hasn’t been shown to improve fertility for women using assisted reproductive technology, such as in-vitro fertilization (IVF).

Keep in mind that if you and your healthcare team decide that a weight-loss medication is an option for you, the newer GLP-1 agonist medications aren’t your only option. Oral weight-loss medications, such as Contrave and Qsymia, are also effective. In most cases, it’s the weight loss itself — not the medication — that helps improve your fertility.

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However, health conditions associated with high blood glucose (sugar) or insulin resistance, such as polycystic ovarian syndrome (PCOS) or type 2 diabetes, can also affect your fertility. GLP-1 related medications can help regulate your blood glucose levels along with weight loss. So if you’re living with one of these conditions, an injectable weight-loss medication may have a greater overall impact on your fertility because of this added effect.

Weight-loss medications may help improve male fertility, too. Losing excess weight can help increase testosterone levels and sexual function as well as sperm count and quality.

Good to know: A low body weight can also have a negative effect on your fertility. A BMI of 18.5 or less is associated with a greater risk of fertility issues. This is because you may not be able to make estrogen and mature eggs properly if you’re considered underweight. Talk to your OB-GYN to help determine if gaining weight may help improve your fertility. And avoid taking weight-loss medications if you don’t qualify for them medically. 

2. Is it safe to take weight-loss medications if you’re trying to become pregnant?

Weight-loss medications aren’t recommended if you’re pregnant or trying to become pregnant in most cases. There are a couple of reasons for this.

First, weight-loss medications may interfere with your baby’s growth and development. Topiramate (Topamax) in particular can increase the risk of birth defects, including a cleft palate. This includes topiramate alone and as part of the combination weight-loss medication Qsymia. In fact, if you’re taking Qsymia, you’ll need to enroll in the FDA’s risk evaluation and mitigation strategy (REMS) program in order to fill your prescription. This program requires monthly negative pregnancy tests to avoid exposing an unborn baby to the medication.

With most other weight-loss medications, the risk of harm is unknown or seems likely based on animal studies. So it’s best to avoid them during pregnancy. 

Second, it’s normal to gain some weight while you’re pregnant. Eating a balanced diet helps both you and your baby stay healthy. Reducing your calories or suppressing your appetite may prevent both you and your baby from getting the nutrients you need.

If you’re taking a weight-loss medication and starting to plan for a family, talk to your healthcare team. They can help you stop taking it safely if needed and let you know when it’s OK to start trying to become pregnant. 

Good to know: Injectable weight-loss medications, such as Wegovy, can stay in your body for quite some time after your last dose. The manufacturer recommends stopping Wegovy at least 2 months before trying to become pregnant. This makes sure enough time has passed to fully clear the medication from your body.

3. Do weight-loss medications interfere with birth control?

Yes, some weight-loss medications can make oral birth control pills less effective. These include:

• Topiramate (in high doses on its own, not as part of Qsymia)

• Wegovy

• Zepbound

GLP-1 related weight-loss medications slow down your digestion. This can lower the absorption of oral birth control and raise the risk of an unwanted pregnancy. This has led to people referring to these unexpected pregnancies as “Ozempic babies.”

Other than topiramate, most oral weight-loss medications won’t cause a problem if you take birth control pills. Qsymia contains a lower dose of topiramate, so it may lead to breakthrough bleeding if you take birth control. But it doesn’t seem to make your birth control less effective.

If you take oral birth control pills to prevent pregnancy, it’s recommended to add a non-hormonal method on top of that if you’re taking one of the above weight-loss medications. This includes options such as a condom or diaphragm. You can also talk to your prescriber about an alternative form of birth control, such as an intrauterine device (IUD), birth control patch, or vaginal ring. Hormonal birth control methods that don’t go through your stomach are unlikely to be affected by weight-loss medications.

4. What should you do if you become pregnant while taking a weight-loss medication?

If you become pregnant while taking a weight-loss medication, contact your healthcare team right away. This can be your regular prescriber or your OB-GYN. They’ll help you weigh the risks and benefits of your current medications to find the best path forward. In most situations, they’ll have you stop taking the weight-loss medication until after you give birth or finish breastfeeding.

Keep in mind that it’s not a good idea to suddenly stop taking a weight-loss medication without talking to a healthcare professional first. In particular, some oral weight-loss medications can be dangerous to stop taking all at once. Your healthcare team can provide instructions for stopping them safely if you become pregnant.

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Written by:

Jill Barat, PharmD

Jill Barat, PharmD has nearly 10 years of experience as a pharmacist, including serving as the pharmacist in charge at an independent sterile and non-sterile compounding pharmacy. She also worked as the head of medical content for a telemedicine company.

Edited by:

Stacia Woodcock, PharmD

Stacia Woodcock, PharmD, is a pharmacy editor for GoodRx. She earned her Doctor of Pharmacy degree from the University of Kentucky and is licensed in New York and Massachusetts.

Reviewed by:

Karen Hovav, MD, FAAP

Karen Hovav, MD, FAAP, has more than 15 years of experience as an attending pediatrician in a variety of clinical settings. She has worked in a large academic center in an urban city, a small community hospital, a private practice, and an urgent care clinic.

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