Does Wegovy Cause Hair Loss?

Telogen effluvium occurs when a larger-than-usual number of hair follicles shift into a resting phase at the same time, leading to noticeable shedding weeks or months later. Rapid changes in body weight, reduced calorie intake, and nutritional shifts — all common during the early stages of a Wegovy journey — are well-recognised triggers for this process. The hair loss itself is typically diffuse (spread across the scalp rather than in patches) and tends to slow down as weight loss stabilises.

Other commonly reported side effects to be aware of

Wegovy works on GLP-1 receptor pathways involved in appetite regulation, and a range of side effects are commonly reported alongside hair changes. These include:

• Nausea — one of the most frequently reported early experiences, often linked to slower stomach emptying. Understanding how GLP-1 medicines affect the body can help put this in context.
• Fatigue and tiredness — some people notice low energy, particularly around dose changes or during periods of lower food intake.
• Headaches — commonly reported, especially in the early weeks. See more on headaches and Wegovy.
• Constipation or changes in digestion — gastrointestinal side effects are among the most discussed; changes in bowel habits, heartburn, and indigestion are all documented.
• Vivid dreams and sleep changes — reported by some users, though less common.
• Anxiety, mood changes, or low mood — any new or worsening mental health symptoms should be discussed with your prescriber or doctor promptly.
• Water retention — some people notice fluid changes, particularly early on.

Digestive changes such as diarrhoea on Wegovy are also worth monitoring, as they can contribute to dehydration and nutritional gaps that may worsen hair shedding.

According to information in the electronic Medicines Compendium (eMC), hair loss (alopecia) is listed among the reported side effects of semaglutide in its prescribing information.

One of the most useful things you can do when you notice something like hair thinning is to log it — when it started, how noticeable it is, and whether it changes over time. GLP Trackr's side-effect tracking feature lets you record exactly this: date, symptom, and severity, so you build a clear picture rather than relying on memory.

That log becomes genuinely useful at prescriber appointments. Instead of trying to recall whether the shedding got worse after a dose change or improved over a particular few weeks, you have a timeline you can actually show. The app's insights tools can also help surface patterns — for instance, whether fatigue or lower food intake seems to coincide with periods of more noticeable hair changes.

For symptoms like anxiety, mood changes, or anything that feels severe or persistent, please contact your healthcare professional promptly rather than waiting for your next scheduled appointment. GLP Trackr is a tracking companion — it helps you notice and record what is happening, but it is not a substitute for clinical advice, and any concerns about your side effects should always be discussed with your prescriber or doctor.

If you are experiencing other digestive side effects alongside hair changes, it may also be worth reading about how digestive changes interact with weight loss, and exploring the broader guide to GLP-1 side effects for more context.

Start logging your side effects and spotting your own patterns — GLP Trackr is free to try for 7 days on the App Store and Google Play.