How your GLP-1 can affect fertility and birth control

Birth rates in the United States have been steadily declining for nearly two decades. That’s made the Ozempic baby boom all the more surprising — women from around the country (and the world) are reporting pregnancies while on a GLP-1, sometimes after years of trying. The evidence is merely anecdotal as of yet, but it’s been enough to make us all wonder: Does Zepbound make you more fertile? Is there some interaction between Ozempic and birth control? What the heck is going on? 

To get the answers, we turned to expert OB/GYNs to learn more about this GLP-1 side effect. Here’s what you need to know — whether you want to prevent pregnancy or plan for it ASAP.

Key takeaways

• GLP-1 medications like semaglutide and tirzepatide may affect contraception and fertility. 

• Tirzepatide can affect the absorption of oral hormonal birth control, so non-oral contraception options like an IUD, patch, or vaginal ring may be the best options. 

• Weight loss can help support fertility and improve insulin resistance in PMOS, which may help restore ovulation and increase the chances of conception.

• These medications should not be taken during pregnancy or while breastfeeding. You should stop taking them under medical supervision about two months before trying to conceive, and then wait to restart until you’re medically cleared during postpartum and have stopped breastfeeding.

Certain GLP-1s reduce the absorption of oral birth control because they slow down digestion. However, the effect on birth control depends on the specific GLP-1 medication. “My first advice is not to assume all GLP-1 medications affect birth control in the same way,” says Dr. Shamsah Amersi, M.D., FACOG, board-certified OB/GYN in Santa Monica, CA. 

Here’s what you need to know about tirzepatide and semaglutide, as well as orforglipron and liraglutide.

Tirzepatide (Mounjaro, Zepbound)

Tirzepatide may reduce oral contraceptive absorption by about 20%, reportedly, due to delayed gastric emptying — possibly decreasing its efficacy. 

This concern is especially high when you start or increase your dose. If you’re taking oral birth control, talk to your clinician before starting the medication. “For women using tirzepatide, I recommend using a backup method, such as condoms, for four weeks after starting the medication and for four weeks after each dose increase,” says Amersi. This is in line with the prescribing information.

Semaglutide (Ozempic, Wegovy)

Although semaglutide also delays stomach emptying, it doesn’t do so to the degree of tirzepatide. “Semaglutide has not been shown to reduce the effectiveness of oral contraceptives," says Amersi. The prescribing information on Wegovy (oral and injection), for instance, does not have a warning about oral contraceptives. Still, if your healthcare provider is prescribing semaglutide, you should talk to them about your contraceptive choice and follow their recommendations.

Orforglipron (Foundayo)

According to the prescribing information, you should talk to your provider before starting Foundayo if you take oral birth control, as it may reduce the efficacy of your birth control. The biggest risk is when you’re starting or upping your dose, in which case your prescriber may advise using an additional backup birth control (such as condoms) for 30 days after starting and after each increase in dose.

Liraglutide (Victoza, Saxenda)

Like semaglutide, liraglutide also delays stomach emptying, so you should discuss its impacts on any oral medication (including oral birth control) with your clinician. That said, in clinical pharmacology trials, liraglutide did not affect the absorption of tested oral medications to a relevant degree.

The most reliable option

If you are taking semaglutide or tirzepatide, you might consider talking to your OB/GYN about using a long-acting reversible contraceptive, suggests Amersi. These include methods like a hormonal IUD (intrauterine device), vaginal ring, or patch, which are not absorbed through the stomach and therefore not affected by slower stomach emptying.

There is a real connection between medications like Ozempic and fertility. “GLP-1s can improve your fertility in certain aspects,” says Dr. Ronni Farris, M.D., FACOG, an OB/GYN in Norman, OK.

Excess weight or obesity can disrupt ovulation, as fat cells release estrogen and excess estrogen suppresses ovulation. Therefore, weight loss itself can help restore normal ovulation, says Amersi. In this way, GLP-1s may improve fertility, but these are not fertility medications, she adds. “We’re also seeing that some women conceive sooner than expected after starting these medications, even before significant weight loss occurs.” That may be due to improvements in metabolic and hormonal health, she says, but more research is needed. 

If you are someone who has PMOS (polyendocrine metabolic ovarian syndrome, formerly polycystic ovarian syndrome, or PCOS), you may struggle with infertility due to a lack of ovulation — caused by high androgen levels, insulin resistance, inflammation, and lower progesterone that may affect implantation. There’s evidence that GLP-1 medications, however, may improve the menstrual cycle and follicle formation, improving ovulation and fertility chances in patients with PMOS. And a combination of GLP-1 and metformin medications have been shown to trigger ovulation in 58% of patients, notes research in Therapeutic Advances in Endocrinology and Metabolism.

Whether you want to prevent pregnancy, improve your chances of conceiving, just found out you’re pregnant, or are in the postpartum phase, there are specific guidelines for taking — or avoiding — GLP-1s. As always, follow the guidance of your healthcare provider.

If you’re actively preventing pregnancy

If you struggled to conceive in the past, you should not assume you are infertile, says Amersi. And given that GLP-1s may improve fertility for some people, you need to use birth control to prevent pregnancy. 

Taking semaglutide or liraglutide? If you’re taking an oral hormonal birth control, you may not need to switch to another mode of birth control, but clear that with your clinician first. 

On tirzepatide or orforglipron? “If pregnancy prevention is especially important, it’s worth discussing a non-oral contraceptive option with your healthcare provider,” says Amersi. If you are sticking with oral birth control, talk to your OB/GYN about having a back-up method of birth control on board during the initial weeks of starting the medication and when increasing your dose. 

If you’re trying to conceive

Time to think about stopping your GLP-1. Although GLP-1s may be helpful for supporting fertility, GLP-1 medications shouldn’t be used if you’re actively trying to get pregnant. According to Wegovy prescribing information, you should stop using semaglutide two months before you’re planning on becoming pregnant. For any GLP-1, Farris tells her patients to stop three months before trying to conceive. Talk to your OB/GYN about the ideal timeframe for you — they may advise you on a shorter or longer wash-out period based on your own needs. 

If you’re already pregnant (or just found out)

You should stop taking tirzepatide, semaglutide, or any other GLP-1 and contact your healthcare provider. There is a possibility that these medications may harm a growing fetus, according to prescribing information. This is largely dependent on your individual health. Your clinician will guide you on safe weight management and metabolic health strategies throughout your pregnancy. 

If you’re breastfeeding

“GLP-1s are not well-studied in breastfeeding, and so there are still many unknowns,” says Farris. Right now, Wegovy (semaglutide) and Foundayo (orforglipron) prescribing information recommends against breastfeeding while on the medication because it’s not yet known if the medication passes into breastmilk. When it comes to medications like Zepbound (tirzepatide) and Saxenda or Victoza (liraglutide), prescribing information advises talking to your healthcare provider, as it may pass into breastmilk. 

One additional concern, says Farris, is that these medications may indirectly reduce milk production. “In the early newborn stage you’re trying to build up your milk supply, which requires consuming a lot of calories. If you’re actively trying to diet and lose weight, you have to be in a calorie deficit, which may affect your milk supply,” she explains. 

If you’re postpartum and thinking about restarting

Talk to your healthcare provider. Amersi says she considers various factors when advising a postpartum patient, which includes how long ago a patient had their baby, if they’ve recovered, as well as nutritional status, mental health, and sleep. “The postpartum period is a time of healing, and it’s important to rebuild healthy habits rather than focus solely on weight loss,” she says. 

After you’ve stopped breastfeeding and it's medically appropriate to do so, you and your clinician can develop a well-rounded plan that includes GLP-1 medication and lifestyle habits.

No matter where you are on your weight-loss journey, if pregnancy is a possibility, talk to your clinician about contraception and fertility while taking semaglutide, tirzepatide, or any other GLP-1. Depending on your family planning goals, questions to ask may include: 

• Is my birth control plan adequate for the GLP-1 I’m taking or should we discuss a back-up plan or switching?

• Can a GLP-1 help ready my body for healthy fertility and pregnancy?

• What lifestyle changes do you recommend I make to support my fertility while I’m not taking a GLP-1? 

• If I decide that I’d like to try to get pregnant, how long in advance do you recommend I stop my GLP-1?  

• What factors will you look at to help me decide if it’s the right time to restart a GLP-1 postpartum? 

This might be a newsflash for some, but Weight Watchers isn’t just one program — it’s many, all of which can be tailored to flex with you through every body change and life stage. 

The Med+ Program gives you access to GLP-1s alongside a nutrition and lifestyle program tailored to life on medication.* If you’re taking a break from your GLP-1 during postpartum or breastfeeding, you can switch over to the Core+ Program that focuses squarely on building and maintaining the habits that are important for your overall wellbeing — think eating nutrient-rich foods and drinking enough water. (There’s even a breastfeeding mode.) And when your body inevitably shifts yet again during perimenopause, the Menopause Program has your back, including access to hormone therapy, if deemed appropriate.

GLP-1s aren’t fertility medications, but their weight loss, metabolic, and hormonal benefits may help support your fertility. On top of this, they may also make your oral contraception less effective, upping your chances for pregnancy — but this depends on the specific medication. Experts advise that you should not take a GLP-1 during pregnancy, and recommend that you stop them about two months prior to trying to conceive. If you are breastfeeding, your clinician will likely advise waiting until you’re done to restart a GLP-1. Of course, these are all general guidelines, and the best choices for you should be made during a discussion between you and your clinician.