GLP-1 and Fertility: Pregnancy Safety and PCOS Effects

You are thinking about starting GLP-1 treatment, or you are already using it. If you are hoping to become pregnant soon, or if pregnancy is unexpected while on medication, you have questions that need clear, honest answers. This article covers what the prescribing information and research show, what it means for your fertility goals, and what you need to know about timing and safety.

GLP-1 medications are not approved for use in pregnancy

GLP-1 medications are not used during pregnancy, but the FDA labels differ on timing. The Wegovy (semaglutide) label says to stop at least 2 months before a planned pregnancy because of semaglutide’s long half-life^[4]. The Zepbound (tirzepatide) label says to stop when a pregnancy is recognized and does not list a specific washout period before a planned pregnancy^[5]. The caution exists because:

1. Insufficient human safety data. Both labels say the available data in pregnant patients are insufficient to establish a drug-related risk of major birth defects, miscarriage, or other adverse outcomes^[4][5]. No one can offer guarantees about safety in pregnancy, because the data do not exist yet.

2. Animal reproduction studies. In animal studies described on the labels, semaglutide and tirzepatide were linked to fetal harm, including growth reductions and structural abnormalities, at clinically relevant exposures^[4][5]. These findings do not prove harm in humans, but when animal data raise concerns and human data are limited, the regulatory response is conservative.

3. Weight loss offers no benefit in pregnancy. Both labels state that weight loss offers no benefit to a pregnant patient and may cause fetal harm^[4][5]. In the animal studies, the fetal effects coincided with reduced maternal weight and food intake, so it is not clear how much comes from the medication itself versus the weight loss it causes. Either way, an unclear mechanism does not equal safety evidence.

For these reasons, the guidance is: do not use GLP-1 medications during pregnancy, plan the stop date with your prescriber based on the label for your medication (at least 2 months before trying to conceive for Wegovy), and if you discover you are pregnant while taking the medication, stop it and call your provider.

If you discover you are pregnant while on GLP-1

Stop the medication and contact your provider right away. Human data on early, unplanned exposure are limited, and the labels say they are insufficient to establish a drug-related risk^[4][5]. Your provider may recommend monitoring or additional ultrasounds. Continue prenatal care and follow your provider’s guidance. The Wegovy label also lists a pregnancy exposure registry run by Novo Nordisk that collects outcomes for people exposed during pregnancy^[4].

The medication should not be continued past this point, but early, unplanned exposure is different from ongoing use throughout pregnancy. Your provider is the best source for what monitoring or reassurance may be helpful in your specific situation.

How GLP-1 can improve fertility: the obesity-infertility connection

Here is where the story gets more nuanced.

Obesity is associated with a specific pattern of reproductive dysfunction in women^[1]. It is not about being “overweight and unhealthy in a general sense.” It is about how excess adipose tissue and insulin resistance disrupt the hormonal signals that drive ovulation.

The mechanism:

Obesity and insulin resistance can disrupt the hypothalamic-pituitary-ovarian (HPO) axis, the hormonal control system for ovulation^[1]. Here is what happens:

1. Elevated insulin and insulin resistance. Excess adipose tissue makes the body resistant to insulin. The pancreas compensates by producing more insulin. In women with PCOS who are not ovulating, high insulin tends to go along with higher luteinizing hormone (LH) levels and more androgen production, which can stop ovulation^[3]. This is called anovulation, and in some women it improves with weight loss.

2. Altered hormone signaling from fat tissue. Adipose tissue acts as a hormone-producing organ. It converts androgens (male-type hormones) to estrogens through the enzyme aromatase and releases other signaling molecules that interact with insulin resistance and egg development^[1]. These changes can disrupt the feedback loop that triggers ovulation.

3. PCOS amplification. Women with polycystic ovary syndrome (PCOS), a common hormonal condition in women of reproductive age, are particularly vulnerable. The 2023 international PCOS guideline describes insulin resistance as a key feature of PCOS^[2]. Obesity can worsen it, and the combination of PCOS and obesity often results in persistent anovulation and infertility.

The weight loss effect:

Lifestyle changes that lead to weight loss have been shown to restore menstrual cycles and ovulation in some women with obesity^[1]. In one small study of 18 women with obesity, PCOS, and anovulation, a 6-month diet and exercise program without rapid weight loss restored ovulation in some participants, along with less central fat and better insulin sensitivity^[3].

When weight loss helps:

1. Insulin sensitivity improves. Circulating insulin levels drop. In the women who started ovulating again in that study, fasting insulin and LH levels both fell^[3].

2. Hormone signaling moves back toward normal. Less excess adipose tissue means less hormonal disruption from fat tissue. The HPO axis feedback loop can begin working again.

3. Ovulation may resume. For some women, menstrual cycles return over time. That can make pregnancy possible. Results vary, and not everyone responds.

GLP-1 and fertility: the documented cases

GLP-1 medications do not work by any direct fertility mechanism. They do not increase hormone levels or stimulate ovaries. What they do is reduce appetite and slow gastric emptying, making it easier for people to sustain a calorie deficit and lose weight.

For women with obesity-related anovulation or PCOS-related infertility, this can indirectly affect fertility by enabling weight loss that may restore ovulation.

There have been reports, many of them anecdotal, of unexpected pregnancies in women who:

1. Had been infertile due to anovulation driven by obesity or PCOS.
2. Started GLP-1 treatment and achieved weight loss.
3. Resumed ovulation during the treatment, sometimes without realizing it.
4. Became pregnant without intentionally stopping the medication or timing it around a conception plan.

How often this happens is not well measured. The key takeaway: if you are on GLP-1 and you have a history of obesity-related anovulation or PCOS, be aware that your fertility status may change. Ovulation may resume. If you do not want to become pregnant, use effective contraception. The 2023 international PCOS guideline advises effective contraception when pregnancy is possible for women taking GLP-1 medications^[2].

Contraception: a critical practical issue

This is the flip side of the fertility coin. If you are on GLP-1 and you do not want to become pregnant, you need to be intentional about contraception. Here is why:

Oral contraceptives and GLP-1 absorption:

GLP-1 medications slow gastric emptying, which can affect how oral medications are absorbed. The Zepbound label warns that tirzepatide may make oral hormonal contraceptives less effective. The effect is largest after the first dose and lessens over time. In a study described on the label, a single 5 mg dose of tirzepatide lowered overall exposure to the pill’s hormones by about 20 percent^[5].

The Wegovy label does not include this warning, and it lists no clinically significant change in ethinyl estradiol or levonorgestrel levels with semaglutide^[4].

Practical recommendation:

For tirzepatide, the label says to switch to a non-oral contraceptive method, or add a barrier method such as condoms, for 4 weeks after starting and for 4 weeks after each dose increase^[5]. If you are on oral birth control and starting or increasing any GLP-1 medication, confirm your backup plan with your prescriber.

Non-oral contraceptives are not affected:

The Zepbound label says hormonal contraceptives that are not taken by mouth should not be affected^[5]. That includes options such as a hormonal IUD, implant, injection, or patch. A copper IUD contains no hormones and does not depend on absorption.

For more detailed information on GLP-1 and birth control options, see the full guide on GLP-1 and birth control.

Male fertility and GLP-1

The data on GLP-1 and male fertility is limited. This is honest uncertainty worth naming.

There is no established evidence that GLP-1 medications harm male fertility. In the animal fertility studies described on the labels, semaglutide had no effect on male fertility in rats, and tirzepatide had no effect on sperm shape, mating, or fertility in rats^[4][5]. Animal results do not always carry over to humans.

Weight loss in men with obesity may be associated with improved testosterone levels and sperm quality. GLP-1 treatment, by supporting weight loss, may indirectly support male reproductive health, but this has not been shown in large trials.

That said, the specific effects of GLP-1 medications on male fertility have not been studied extensively in clinical trials. If you are a man using GLP-1 and you have concerns about fertility, discuss it with your provider. They can order testosterone and semen analysis if indicated by your clinical history.

PCOS and fertility: a detailed connection

If you have PCOS, the fertility angle is particularly important. Insulin resistance and androgen excess are common in PCOS^[2], and lifestyle changes that improve insulin sensitivity have restored ovulation in some women with PCOS and obesity^[3].

GLP-1 treatment supports weight loss, which addresses the insulin resistance component. This may restore ovulation in some women with PCOS who have become anovulatory due to metabolic disruption. The 2023 international PCOS guideline recommends using anti-obesity medications for fertility outcomes only in research settings, until their effectiveness and safety for that purpose are established^[2].

For more detailed information on GLP-1 and PCOS, including how the medications interact with PCOS management, see the full guide on GLP-1 and PCOS.

Summary: timing, safety, and your fertility goals

Here is the practical takeaway:

If you are planning to become pregnant:

Plan the stop date with your prescriber. For Wegovy (semaglutide), the label says to stop at least 2 months before a planned pregnancy because of semaglutide’s long half-life^[4]. For Zepbound (tirzepatide), the label says to stop when a pregnancy is recognized^[5]. While you are on GLP-1 and pregnancy is not yet planned, use reliable contraception.

If weight loss during GLP-1 treatment brings back ovulation, that is a positive sign. Whether it lasts after you stop depends on many factors, including whether the weight stays off. Weight regain after stopping is common^[2], so talk with your prescriber about a plan for after the medication.

If you are already on GLP-1 and you want to remain pregnant:

Stop the medication. Contact your provider. Your provider can discuss monitoring and any needed follow-up care. Human data on early, unplanned exposure are limited^[4][5], and the medication should not be continued.

If you are on GLP-1 and you do not want to become pregnant:

Use reliable contraception. If you take birth control pills and use tirzepatide, the label says to switch to a non-oral method or add a barrier method for 4 weeks after starting and after each dose increase^[5]. Hormonal contraceptives not taken by mouth should not be affected.

If you have PCOS or obesity-related anovulation and you hope to improve fertility:

Weight loss may improve ovulatory function in some women with these conditions, and GLP-1 treatment can support weight loss. It is not a fertility drug, and the 2023 international PCOS guideline recommends anti-obesity medications for fertility outcomes only in research settings^[2]. If you do use one, plan the stop date before trying to conceive based on your medication’s label.

GLP-1 medications are tools for supporting weight loss and metabolic health. Fertility is a part of your health picture, and an important one. Any provider prescribing GLP-1 should be aware of your fertility goals and timeline.

Citations

[1] Silvestris E, et al. “Obesity as disruptor of the female fertility.” Reproductive Biology and Endocrinology 2018;16(1):22. https://pubmed.ncbi.nlm.nih.gov/29523133/ (Obesity and HPO axis disruption, anovulation, adipose tissue as an endocrine organ; lifestyle weight loss restores cycles and ovulation.)

[2] Teede HJ, et al. “Recommendations From the 2023 International Evidence-based Guideline for the Assessment and Management of Polycystic Ovary Syndrome.” Journal of Clinical Endocrinology and Metabolism 2023;108(10):2447-2469. https://pubmed.ncbi.nlm.nih.gov/37580314/ (Insulin resistance as a key feature; GLP-1 medications, contraception, and long-term use; anti-obesity medications for fertility outcomes in research settings only.)

[3] Huber-Buchholz MM, et al. “Restoration of reproductive potential by lifestyle modification in obese polycystic ovary syndrome: role of insulin sensitivity and luteinizing hormone.” Journal of Clinical Endocrinology and Metabolism 1999;84(4):1470-1474. https://pubmed.ncbi.nlm.nih.gov/10199797/ (18 anovulatory women with obesity and PCOS; 6-month lifestyle program; ovulation restored in responders with lower insulin and LH.)

[4] Novo Nordisk. Wegovy (semaglutide) prescribing information. US Food and Drug Administration. Revised 06/2026. https://www.accessdata.fda.gov/drugsatfda_docs/label/2026/215256s025lbl.pdf (Section 8.1: animal data and insufficient human data; section 8.3: stop at least 2 months before a planned pregnancy; section 12.3: no clinically significant change in ethinyl estradiol or levonorgestrel; section 13.1: no effect on male rat fertility.)

[5] Eli Lilly and Company. Zepbound (tirzepatide) prescribing information. US Food and Drug Administration. Revised 08/2026. https://www.accessdata.fda.gov/drugsatfda_docs/label/2026/217806Orig1s041correctedlbl.pdf (Section 8.1: stop when pregnancy is recognized, animal data, insufficient human data; sections 7.2 and 8.3: oral hormonal contraceptive instructions; section 12.3: contraceptive interaction study; section 13.1: no effect on male rat fertility.)