If you're a woman starting a GLP-1, the first thing to know is about fertility, not weight. These medications can make some birth control less reliable, they can bring back ovulation you weren't counting on, and they aren't safe to take in pregnancy. "Ozempic babies" became a headline for a reason. This guide covers contraception, pregnancy planning, PCOS, bone and muscle, the heart and menopause.
Birth control and "Ozempic babies"
Two separate things can lead to an unplanned pregnancy on a GLP-1, and they add up.
The pill can absorb less well. Tirzepatide (Mounjaro, Zepbound) can reduce the absorption of oral contraceptives. The drug slows stomach emptying, which changes how the pill is taken up. The US Zepbound label tells women on the pill to switch to a non-oral method (implant, IUD, injection) or add a barrier method like condoms for 4 weeks after starting and for 4 weeks after each dose increase (Zepbound prescribing information (external link)). Semaglutide (Ozempic, Wegovy) labels carry no such warning. If you're not sure which applies to you, ask your prescriber.
Fertility can come back. Weight loss can restore ovulation in women who weren't ovulating regularly, especially with PCOS. That's welcome if you want to conceive and a surprise if you don't.
In June 2025 the UK regulator, the MHRA, urged women taking GLP-1s for weight loss to use effective contraception. Its main reason was that there isn't enough safety data to know whether these drugs harm a baby, and it also flagged the tirzepatide pill interaction (Pharmaceutical Journal, 5 June 2025 (external link)).
So if you don't want to be pregnant, use a reliable non-oral method, or back up the pill, while you're on a GLP-1.
If you're pregnant, or planning to be
GLP-1 medications are not recommended in pregnancy, while trying to conceive, or while breastfeeding. Human safety data are insufficient, and animal studies raised concerns. Because these drugs clear from the body slowly, the usual advice is to stop before trying to conceive and allow a wash-out period, not to wait for a positive test.
The timing depends on the drug and on whose guidance you follow. The US Wegovy label says to stop semaglutide at least 2 months before a planned pregnancy because of its long half-life (Wegovy prescribing information (external link)). The UK MHRA's June 2025 guidance says at least two months for semaglutide and at least one month for tirzepatide. The US Zepbound label doesn't set a pre-conception wash-out; it says to stop the drug when pregnancy is recognized. Confirm the number for your drug with your prescriber. If you become pregnant unexpectedly while taking one, contact your prescriber promptly.
PCOS: often where GLP-1s help most
Polycystic ovary syndrome is common, strongly tied to insulin resistance and excess weight, and a leading cause of irregular cycles and infertility. It's one of the areas where these medications look most promising. A 2026 review calls GLP-1 receptor agonists an attractive weight-loss option in PCOS, while noting that PCOS-specific data are still limited and that there are safety questions around conception (Prentice & Rassie, Drug and Therapeutics Bulletin, 2026, DOI (external link)).
The benefits go beyond weight. A meta-analysis of 7 randomized trials (330 women with PCOS) found liraglutide increased menstrual frequency, lowered BMI and insulin resistance, and reduced LH and free androgen index (Lu et al., Diabetes, Obesity & Metabolism, 2026, DOI (external link)). A second meta-analysis of 12 trials found that adding liraglutide to metformin improved ovulation and spontaneous-conception rates compared with metformin alone (Huang & He, BMC Women's Health, 2025, DOI (external link)).
Smaller randomized trials with other GLP-1s point the same way. In 60 women, exenatide plus metformin improved menstrual cycles and ovulation more than either drug alone (Elkind-Hirsch et al., Journal of Clinical Endocrinology & Metabolism, 2008, DOI (external link)). In 176 women, 12 weeks of exenatide was followed by a higher natural pregnancy rate than metformin (43.6% vs 18.7%) (Liu et al., Clinical Endocrinology, 2017, DOI (external link)). And in 100 women, semaglutide plus metformin led to more menstrual-cycle recovery and a higher natural pregnancy rate than metformin alone (35% vs 15%) (Chen et al., Reproductive Biology and Endocrinology, 2025, DOI (external link)). Case reports describe the same thing in individual patients (Nicolaou et al., Cureus, 2025, DOI (external link)). There are no comparable fertility trials for tirzepatide yet.
That brings you back to contraception: better PCOS control can mean fertility returns.
Menopause and the body-composition shift
Menopause changes where the body stores fat and how easily it holds muscle. That's the same ground a GLP-1 works on, which is why hormone therapy and these medications keep coming up together. They are different tools that can work alongside each other. Our guides on HRT for women and GLP-1 medications and the HRT and GLP-1 overview cover how they fit.
Bone and muscle
Women have a higher lifetime risk of osteoporosis, and bone loss speeds up around and after menopause. Rapid weight loss takes some bone and lean mass along with fat, so it's worth protecting both. Resistance training preserves muscle and loads bone (see why strength training matters on a GLP-1). You need enough protein even when your appetite is low (high-protein meals and snacks when your appetite is low), plus adequate calcium and vitamin D (supplements on a GLP-1). For the bone-density and fracture evidence, including trials where exercise protected bone during weight loss, and for when a bone scan makes sense, see protecting your bones on a GLP-1.
The heart
Cardiovascular disease is the leading cause of death in women, and a Lancet commission describes it as understudied, under-recognised, underdiagnosed and undertreated in women (Vogel et al., The Lancet, 2021, DOI (external link)). GLP-1s pull in a helpful direction. In a large 2025 real-world study of adults with obesity, GLP-1 use was associated with lower rates of major adverse cardiovascular events and all-cause mortality than other weight-loss medications (Tang et al., Diabetes, Obesity & Metabolism, 2025, DOI (external link)). The benefit still depends on staying in touch with your care team and keeping up with your labs.
The mental and body-image load
Rapid body change hits emotionally. For many women it lands on top of a long history of weight talk, dieting and how the world reacts to their appearance. If your self-image is lagging behind the mirror, that's common. Our guide on body-image lag versus body dysmorphia explains the difference and where to get help.
What this adds up to
The way a GLP-1 causes weight loss is the same for everyone, though women tend to lose somewhat more on average (see GLP-1s in men vs women). What's different for women is fertility. Put contraception at the top of your first conversation with your prescriber, and plan any pregnancy around a wash-out period.
This article is general education, not medical advice. Contraception, pregnancy, and PCOS decisions are individual and time-sensitive, so confirm the specifics for your medication with your prescriber. Do not start, stop, or change any medication based on this article alone. Research findings above are attributed to PubMed-indexed articles with DOI links.