GLP-1 Medications and Fertility: What You Need to Know Before, During, and After Pregnancy

What do GLP-1 drugs do for fertility?

Most of the published work frames obesity itself as the fertility problem. A 2020 review in the Journal of Clinical Endocrinology and Metabolism notes that women with obesity have poorer reproductive outcomes regardless of how conception occurs, and that weight reduction is the most significant factor affecting fertility and pregnancy outcomes [5].

How much weight these drugs take off depends on the agent. A 2025 narrative review in Reproductive Biology and Endocrinology puts weight loss with the available agents at roughly 6% to 30% of starting body weight, and its authors argue that their efficacy and relative safety make GLP-1 receptor agonists first-line options for women seeking to lose weight in the year before trying to conceive [6]. That is a review opinion, not a trial result.

What the labels say about pregnancy

For Wegovy, the label says available pharmacovigilance data and clinical trial data in pregnant patients are insufficient to establish a drug-associated risk of major birth defects, miscarriage or adverse maternal or fetal outcomes. It also says weight loss offers no benefit to a pregnant patient and may cause fetal harm, and says to discontinue Wegovy in pregnant patients who are using it for weight reduction when a pregnancy is recognized [1].

The animal findings behind the warnings are specific. In rats given semaglutide during organogenesis, the label reports embryofetal mortality, structural abnormalities and altered growth at clinically relevant maternal exposures [1]. In a combined fertility and embryofetal development study, offspring showed reduced growth and visceral (heart blood vessels) and skeletal (cranial bones, vertebra, ribs) abnormalities at clinically relevant exposures at the maximum recommended human dose [1].

The Foundayo (orforglipron) label reaches a similar conclusion. It states that there are no adequate and well-controlled studies in pregnancy, that weight loss offers no benefit in pregnancy and may cause fetal harm, and that Foundayo should be discontinued when a pregnancy is recognized [2]. It notes that imbalances in malformations have been reported in rats and rabbits with GLP-1 receptor agonists active in those species, that orforglipron is not pharmacologically active in rats and rabbits, and that pregnant monkeys given oral orforglipron during organogenesis at doses below the maximum recommended human dose had no embryofetal effects; higher doses and exposures could not be evaluated in monkeys [2].

The Wegovy label describes a pregnancy exposure registry run by Novo Nordisk (1-877-390-2760 or wegovypregnancyregistry.com), and the Foundayo label says a registry will monitor outcomes in women exposed to orforglipron during pregnancy [1][2].

Where does the two-month figure come from?

The 2-month interval is written into the Wegovy label: patients receiving semaglutide for cardiovascular risk reduction or weight reduction should discontinue it at least 2 months before a planned pregnancy because of the long half-life of semaglutide [1]. Semaglutide's half-life is about 1 week [1][8].

For tirzepatide, the Zepbound label's instruction is to discontinue when pregnancy is recognized, and it states that weight-loss use offers no benefit in pregnancy [3]. A 2026 review of GLP-1 drugs and fertility describes an 8-10 week washout before conception for both semaglutide and tirzepatide [4].

Stopping has a cost in weight. In STEP 4, 803 adults who had completed 20 weeks of semaglutide were randomized to continue or switch to placebo for 48 weeks; the placebo group gained 6.9% of body weight while the continuing group lost a further 7.9% [9].

Does a GLP-1 drug interfere with birth control?

This differs by drug, and the labels are explicit where it applies.

The tirzepatide label advises patients using oral hormonal contraceptives to switch to a non-oral method or add a barrier method for 4 weeks after starting and for 4 weeks after each dose increase [3]. The Foundayo label gives the same advice for 30 days after initiation and after each dose escalation, and states that hormonal contraceptives not taken orally should not be affected [2].

The semaglutide labels carry no such advice, and a tablet interaction study found no clinically significant change in ethinyl estradiol or levonorgestrel exposure [1]. The 2026 review attributes the tirzepatide concern to delayed gastric emptying [4]; the Wegovy and Foundayo labels say delayed gastric emptying can change the absorption of oral medicines [1][2].

GLP-1 drugs and PCOS

Polycystic ovary syndrome is one of the leading causes of infertility, and many women with PCOS also have obesity [5]. A 2026 review of 47 articles concluded that GLP-1 receptor agonists show consistent metabolic benefits and emerging evidence of improved reproductive outcomes in PCOS, with trials reporting increased menstrual regularity, ovulation and pregnancy rates, particularly when combined with metformin [4].

That review gives two concrete numbers. In one randomized trial, pregnancy rates were higher with liraglutide plus metformin (69.2%) than with metformin alone (35.4%, P<0.05), and ovulation rates up to 86% have been described with exenatide plus metformin [4]. Liraglutide at 1.2 to 3.0 mg per day and exenatide 10 mcg twice daily were the regimens associated with improved follicular development and endometrial receptivity [4].

The earlier literature is less tidy. A 2020 review found that several studies of GLP-1 receptor agonists, mainly liraglutide, in women with obesity and PCOS showed significant weight loss and testosterone reduction, with mixed results for insulin resistance and menstrual patterns [5]. A 2019 review in Human Reproduction Update found GLP-1 receptors throughout the reproductive system and, from preclinical models and a few clinical studies, suggested a stimulating role for GLP-1 and its mimetics in reproduction that goes beyond weight reduction, along with anti-inflammatory and anti-fibrotic effects in gonads and endometrium affected by obesity, diabetes and PCOS [10].

Male fertility

A 2023 narrative review found GLP-1 receptors within the male reproductive system and reported that weight loss with GLP-1 receptor agonists correlated with improvements in sperm count, concentration and motility in the clinical trials it examined [11]. The same review concluded that the direct effect of these drugs on male reproductive hormones remains unclear [11].

After delivery: breastfeeding

The Wegovy label states that breastfeeding is not recommended during treatment with Wegovy tablets [1]. A 2026 review of GLP-1 receptor agonists and fertility concludes that these drugs should be avoided during both pregnancy and lactation [4].

What is still unknown

A 2019 review concluded that understanding of GLP-1's role in reproduction is limited and largely unaddressed in clinical studies [10]. For pregnancy, the Wegovy label says the available human data are insufficient to establish a drug-associated risk of major birth defects, miscarriage or adverse maternal or fetal outcomes [1].