Semaglutide During Pregnancy: the Clear Guidance

You've found out you're pregnant while on Wegovy, here's what to do first

The situation is more common than many people expect. Semaglutide can affect how the body absorbs oral medicines, including the contraceptive pill, which means some women on Wegovy have become pregnant without anticipating it. One misconception worth naming gently: some people assume that because GLP-1 medicines suppress appetite and affect hormones, they might prevent pregnancy altogether. They do not act as contraception, and unintended pregnancies do occur.

If you discover you're pregnant while taking semaglutide, the immediate step is to contact your GP or midwife rather than stopping the injection on your own. Abruptly halting any medicine during early pregnancy without clinical input is rarely the right move, and your GP will weigh up your overall health, including whether any underlying conditions the medicine was supporting need managing differently. There is no evidence that a single or small number of doses before a positive test causes harm, but continuing through pregnancy is not appropriate.

The NHS medicines page for semaglutide is explicit: tell your doctor straight away if you become pregnant during treatment. That is the clearest practical instruction, and it holds whether you are using the injectable form or any other semaglutide product. For more detail on what the research currently shows about outcomes, our page on whether semaglutide affects pregnancy goes through the animal and human data carefully.

Why semaglutide is not suitable during pregnancy

The core problem is one of evidence, not just caution. Clinical trials of semaglutide excluded pregnant participants, which means there is no large-scale human safety dataset. Animal studies, conducted at doses proportionally higher than those used in people, showed reduced foetal body weight and skeletal abnormalities in some species. The SmPC for Wegovy, published on the Electronic Medicines Compendium, therefore contraindicates use during pregnancy on the basis of precautionary principles.

Beyond the animal data, there is a physiological rationale for concern. Semaglutide slows gastric emptying and reduces overall calorie absorption. A growing foetus depends on the mother's nutritional intake, and anything that materially reduces it carries risk during the critical windows of organ formation in the first trimester. The caloric restriction that makes Wegovy effective for weight loss is precisely the mechanism that makes it unsuitable when that same nutrition needs to support a developing pregnancy.

There is also a pharmacokinetic consideration: semaglutide has a half-life of approximately one week, meaning it remains active in the body for several weeks after the last dose. This is why guidance recommends stopping the medicine well before conception rather than just on the day of a positive test, and our dedicated page on semaglutide and pregnancy brings together the key guidance on timing and next steps. Our page on the pregnancy category for semaglutide covers the regulatory classification in more detail.

Planning ahead: stopping semaglutide before you try to conceive

For anyone thinking about starting a family, the conversation with your prescriber should happen well in advance. Because of semaglutide's extended half-life, most clinical guidance recommends allowing a meaningful wash-out period after stopping before actively trying to conceive. The exact timing is a clinical decision based on your individual circumstances, your dose, and any weight-related conditions that need ongoing management.

Weight management itself remains important in pregnancy planning: excess weight is associated with a higher risk of gestational diabetes, pre-eclampsia and other complications, and clinicians often recommend stabilising weight before conception rather than losing weight during pregnancy. Stopping Wegovy does not mean stopping care. Your GP can discuss what support is available through NHS weight management pathways, and our Wegovy and pregnancy page covers the planning considerations from both angles.

If cost or access has been a factor in your treatment, it is worth knowing that private treatment through a regulated service can continue to support you with monitoring and aftercare until the point you choose to stop, with transitions managed properly. You can read more about how Wegovy is prescribed and monitored at nume, or explore the broader weight-loss treatment options available. For anything specific to your situation, our prescribers are available seven days a week, contact us or speak to our prescribers directly.

Breastfeeding, fertility and the wider picture

The guidance extends beyond pregnancy itself. Semaglutide is also not recommended during breastfeeding: it is not known whether the medicine passes into breast milk in humans, and the developmental risk to a nursing infant cannot be ruled out. Women are therefore advised to stop breastfeeding if semaglutide treatment is necessary, or to stop the medicine if breastfeeding is the priority. In most weight-management contexts, breastfeeding takes precedence and treatment is paused.

On fertility specifically, current evidence does not suggest semaglutide directly impairs fertility, some data actually indicates that weight reduction can improve reproductive outcomes in women with obesity-related conditions such as polycystic ovary syndrome. But the medicine itself is not studied in fertility treatment, and anyone navigating fertility treatment alongside weight management should discuss both with their specialist before making any changes. The NHS England guidance on weight management injections addresses contraception and reproductive planning in useful detail. Our page on semaglutide's effects on pregnancy explores the fertility dimension further.