Does Wegovy Cause Hair Loss? Why It Happens and Whether It Grows Back

Short answer: Wegovy (semaglutide) can cause hair loss. The UK product information (SmPC, section 4.8) lists it as a common side effect, which may affect up to 1 in 10 people. In the main trials it was reported by 2.5% of people on Wegovy 2.4mg against 1.0% on placebo, and by 5.3% on Wegovy 7.2mg against 1.0% on placebo in the STEP UP trials. Individual results vary. It was mainly mild, most people recovered while they carried on with treatment, and it was reported more often in people who lost 20% or more of their weight. It is usually shedding after weight loss, not permanent hair loss.

This guide sets out what the UK product information, the NHS and the British Association of Dermatologists say, as of October 2026: how common hair loss is on Wegovy injections and tablets, why it happens, how long it lasts, whether it grows back, what helps, and when to see a GP.

Does Wegovy cause hair loss?

Yes, hair loss is a recognised side effect of Wegovy. The product information puts it in the "common" group, alongside side effects such as indigestion, dizziness and gallstones, and the patient leaflet in every pack lists it the same way. The NHS page on semaglutide, the medicine in Wegovy, also lists hair loss among its common side effects. Hair loss is not unique to Wegovy: it is listed for Mounjaro and Foundayo too, and the NHS names weight loss itself as one cause of temporary hair loss.

What people usually notice is more hair than normal coming out when they wash or brush it, and hair feeling thinner overall, rather than bald patches. Our guide to Wegovy side effects covers the full list, and weight loss injection side effects compares the medicines we supply.

How common is hair loss on Wegovy?

Hair loss affects a small minority of people on Wegovy, more at the higher dose. In the four main trials behind the UK product information, which ran for 68 weeks, it was reported by 2.5% of people on Wegovy 2.4mg and 1.0% on placebo. In the STEP UP trials, which ran for 72 weeks, it was reported by 5.3% of people on Wegovy 7.2mg and 1.0% on placebo. Individual results vary.

Each chart sets Wegovy against placebo within the same trials. These were separate trials in different groups of people, so the figures are not a direct comparison. Individual results vary.

With Wegovy tablets, in the 64-week OASIS 4 trial, hair loss was reported by 6.4% of people on the tablets and 2.0% on placebo. Individual results vary. Put the other way round, more than 9 in 10 people in each of these trials did not report hair loss.

Why does hair fall out on Wegovy?

For most people it is shedding brought on by weight loss, which dermatologists call telogen effluvium. The British Association of Dermatologists explains that, at any one time, around 85% of the hair follicles on your scalp are growing and around 15% are resting. A resting follicle rests for two to four months, then a new hair grows and pushes the old one out. A big change for the body, such as illness, stress or marked weight loss and extreme dieting, can move far more follicles into the resting phase at once, 30% or more, and those hairs then shed together.

The Wegovy product information does not explain the cause, but it does say hair loss was reported more often in people who lost 20% or more of their weight. The product information for Foundayo, another GLP-1 medicine, describes its hair loss as temporary and linked to weight reduction. Eating much less matters too: the British Dietetic Association says that not eating enough on these medicines can leave you dizzy and tired, or lose hair. A low iron level is another cause of temporary hair loss the NHS names, and the dermatologists add that shedding can come back if a cause such as low iron is not treated.

When does it start and how long does it last?

The product information does not say when hair loss starts on Wegovy, so timing varies. Shedding of this kind often starts suddenly, around 3 months after the trigger, according to the British Association of Dermatologists. So on Wegovy it is more likely to show some months into treatment, once weight loss is under way, than in the first few weeks.

The shedding phase usually lasts 3 to 6 months. Most people lose between 30 and 150 hairs a day anyway, so a few more on the brush is normal. Shedding that carries on for more than 6 months is called chronic, and is a reason to see your GP.

Does hair grow back after Wegovy?

In most cases, yes. In the Wegovy injection trials, hair loss was mainly mild and most people recovered while they carried on with treatment, without stopping Wegovy. In the OASIS 4 trial of Wegovy tablets, every case was mild or moderate, and half of those affected had recovered by the end of the 64-week trial.

The British Association of Dermatologists says telogen effluvium usually gets completely better without any treatment: once the shedding phase ends, new hair starts to grow. It can take many months for your hair to get back to its usual thickness. The NHS says the same of most temporary hair loss: it grows back. One exception to know about: the dermatologists note that a shed can bring male or female pattern hair loss to light earlier, and that the two can appear at the same time. Pattern hair loss is a separate condition, which the NHS describes as permanent.

Is hair loss worse on Wegovy 7.2mg?

Hair loss was reported more often at 7.2mg. In the STEP UP trials it was reported by 5.3% of people on Wegovy 7.2mg against 1.0% on placebo; in the earlier trials of 2.4mg it was 2.5% against 1.0%. These were separate trials in different groups of people, so the figures are not a direct comparison. Individual results vary.

The patient leaflet says hair loss "may occur more frequently with semaglutide 7.2 mg". The 7.2mg dose is for adults with a BMI of 30 or above, after at least 4 weeks on 2.4mg.

The product information does not say why. One likely part of it is weight: in the STEP UP trial (The Lancet Diabetes and Endocrinology, 2025), adults with a BMI of 30 or above lost an average of 18.7% of their body weight on 7.2mg over 72 weeks, against 15.6% on 2.4mg and 3.9% on placebo, counting everyone who started treatment. Individual results vary. Hair loss was reported more often in people who lost more weight. More on the higher dose is in our guide to Wegovy 7.2mg.

Does the Wegovy pill cause hair loss?

Yes, Wegovy tablets can cause hair loss too, because they contain the same medicine, semaglutide. Their product information lists hair loss as common. In the 64-week OASIS 4 trial it was reported by 6.4% of people on the tablets and 2.0% on placebo. Individual results vary. Every case was mild or moderate, and half had recovered by the end of the trial. This is how our counselling for the tablets describes it:

The figures for the tablets and the injections come from different trials, so they are not a direct comparison. The other side effects of the tablets are in our guide to Wegovy tablets side effects.

What helps with hair loss on Wegovy?

Eating well, being gentle with your hair and giving it time help most. The British Association of Dermatologists says there is normally no treatment needed, and that taking medication does not speed up regrowth. These are the steps its leaflet, the British Dietetic Association and our pharmacists suggest:

• Protein at every meal. Eat the protein on your plate first. If you would like a number, a 2025 joint advisory from four obesity and nutrition societies suggests 80 to 120g a day. If you have kidney disease, check with your GP or pharmacist before you eat more protein.

• A balanced diet with iron. The dermatologists suggest food rich in iron and protein, with fresh fruit and vegetables. When you are eating less, regular balanced meals matter more, not less.

• Be gentle with your hair. Avoid harsh brushing, limit hairdryers, straighteners and curlers, avoid bleaching or relaxing treatments, and keep tight hairstyles to a minimum.

• Talk to your pharmacist. Your pharmacist reviews you before each dose increase. A slower dose increase is often possible, and stopping is not the only option.

If you are not eating much, our guide to what to eat on Wegovy has meal ideas that are easier to manage, and vitamins on Mounjaro and Wegovy explains which nutrients can run low when you eat less. The dermatologists suggest considering supplements if your diet is restricted, for example if you are vegan or vegetarian; none of the sources here recommends biotin for this kind of shedding. Ask your pharmacist before starting any supplement.

When should you see a GP about hair loss?

See a GP if you are worried about your hair loss, the NHS advises. Hair loss is not usually anything to worry about, but occasionally it can be a sign of a medical condition, and a GP may be able to tell what is causing it by looking at your hair. Tell them if it is affecting how you feel. These are good reasons to book an appointment:

• Hair coming out in patches. Shedding after weight loss thins hair all over the scalp rather than in patches.
• Shedding that is not getting better, or has gone on for more than 6 months.
• Thinning that keeps getting worse, especially if baldness runs in your family, as male and female pattern baldness usually does.
• Other symptoms alongside it. A GP may check your blood for causes such as a thyroid problem or low iron.

The NHS also advises seeing a GP before paying a commercial hair clinic. If you are a man and a GP or pharmacist thinks you have male pattern hair loss, that is what our hair loss service treats, after a consultation reviewed by a GPhC-registered pharmacist. It is a different condition from shedding on Wegovy.

Should you stop Wegovy because of hair loss?

Not without talking to your pharmacist first. In the trials, most people with hair loss on Wegovy injections recovered while they carried on with treatment. The NHS advises speaking to a pharmacist or doctor about any side effect that bothers you or does not go away, and keeping taking your medicine unless you are advised to stop.

Message your pharmacist through your account if shedding worries you. We can look at how fast your weight is coming off, how much you are eating and whether your next dose increase should wait. If you do decide to stop, plan it with us:

Treatment works alongside a reduced-calorie diet and regular activity. Aim for at least 150 minutes a week. Weight loss naturally slows over time, and stopping treatment without keeping lifestyle changes commonly leads to weight regain, so we review you regularly and plan any stop together.

Is hair loss more common on Wegovy or Mounjaro?

There is no way to say from the evidence, because the two medicines have not been compared for hair loss in the same trial. Each product information gives a figure from its own trials, and hair loss is listed as common for every GLP-1 medicine we supply:

These were separate trials in different groups of people, so the figures are not a direct comparison. Individual results vary.

For both Wegovy and Mounjaro, the product information says the hair loss was mainly mild and most people recovered while they carried on with treatment. Which medicine suits you depends on your health, your medicines and your goals, and the pharmacist decides with you. The Mounjaro side of the question is in our guide to whether Mounjaro causes hair loss.