Does Wegovy change your period — and what should you expect?

Step 1: understand why weight loss itself affects your hormones

The first thing to know is that Wegovy's effect on periods is mostly indirect. Fat tissue produces and stores oestrogen; as your body composition changes, oestrogen levels shift too. A drop of 5–10% of body weight can be enough to alter the regularity, length or heaviness of a cycle. This is not unique to Wegovy, it happens with any intervention that produces meaningful weight loss.

That hormonal recalibration can also work in the other direction. Women who previously had irregular cycles related to excess weight, or to conditions such as polycystic ovary syndrome (PCOS), sometimes find their cycle becomes more regular as weight falls. PCOS is strongly associated with insulin resistance, and GLP-1 medicines like semaglutide influence insulin signalling, so some improvement in cycle regularity may be an indirect benefit. The NHS overview of semaglutide does not list menstrual disruption as a recognised side effect of the medicine itself, which supports the view that the hormonal shifts are metabolic rather than pharmaceutical.

In short: changes to your period on Wegovy are real, but they are almost always a consequence of the treatment working, not a warning sign that something has gone wrong.

Step 2: know the contraception rule, and whether Wegovy affects the pill

This is where the two main GLP-1 medicines differ in one practical way. Wegovy slows gastric emptying, which can theoretically affect how quickly oral medicines are absorbed. NHS England's guidance on weight-management injections notes that, unlike tirzepatide, there is no current evidence that semaglutide reduces the effectiveness of the oral contraceptive pill. Women on tirzepatide are advised to add a barrier method for the first four weeks of treatment and after each dose increase; the equivalent precaution is not stated for semaglutide at present.

That said, the MHRA advises using contraception while on GLP-1 medicines regardless, because fertility can return or increase as weight changes, particularly in women who had reduced fertility before starting. A cycle that returns or becomes more predictable is a positive sign, but it also means ovulation may resume. If pregnancy is not planned, speak to your prescriber about the most reliable contraceptive option for you. A full overview of Wegovy covers the licensed indications and prescribing criteria in more detail.

Step 3: recognise what needs medical attention

Most cycle changes on Wegovy settle within a few months as your weight stabilises. Lighter periods, some irregularity in the first few cycles, or a temporary pause are generally not causes for alarm. There are situations, however, that deserve a prompt conversation with a clinician.

Get in touch with your prescriber or GP if: periods stop entirely for three months or more without a clear explanation; bleeding becomes unusually heavy or prolonged; you have significant pelvic pain; or you think you might be pregnant. These could point to causes unrelated to Wegovy that need investigating. Anyone with a history of hormone-sensitive conditions should raise this at their initial consultation before starting treatment.

If you are unsure whether what you are experiencing is within the range of normal, our team is available for aftercare seven days a week. You can also read more about Wegovy and period changes or explore related questions about whether semaglutide can stop your period altogether, both pages go deeper into the evidence and the clinical picture.

Step 4: pregnancy, breastfeeding and planning ahead

Wegovy is not licensed for use in pregnancy or while breastfeeding, and is not recommended for anyone trying to conceive. These exclusions are standard for GLP-1 receptor agonists and are set out in the medicine's Summary of Product Characteristics. If you become pregnant while on treatment, stop taking Wegovy and contact your healthcare team promptly.

The wash-out period before trying to conceive (the time recommended between stopping Wegovy and attempting pregnancy) should be confirmed with your prescriber based on current guidance; it is one of the clinical questions reviewed before any prescription is issued. For broader questions about Wegovy and your situation, our FAQs page covers a range of clinical scenarios, including whether Wegovy changes your taste and how that can affect eating habits over time. Our prescribers also review reproductive health history as part of every assessment of whether Wegovy is suitable, so nothing needs to go unasked.

If you are ready to find out whether Wegovy is clinically right for you, a real prescriber (not an automated system) reads every consultation the same day it arrives. You can check your eligibility through our free online consultation, and if you are currently on a different GLP-1 medicine you can find out how to change to Wegovy and what that process involves. If approved, treatment is dispatched the same day for free next-working-day delivery; the pen arrives in plain, unbranded packaging with a DPD tracking link so you know exactly when to expect it.