Short answer: Wegovy (semaglutide) is licensed by the MHRA, the UK medicines regulator, for weight management in adults with a BMI of 30 or above, or 27 or above with a weight-related condition, and it has been studied in trials of thousands of people, the longest following them for more than three years on average. Most side effects are stomach and bowel symptoms that settle with time. Serious problems such as pancreatitis are uncommon, and a sudden loss of vision (NAION) is very rare. It is not suitable for everyone: it must not be used in pregnancy and should not be used while breastfeeding, and your health and medicines should be checked before you start.
This guide sets out what the UK product information and the MHRA say, as of October 2026: what Wegovy does, who should not take it, how common each side effect is, the rarer serious risks and what to do about them, and how to make sure your pen is genuine.
What does Wegovy do?
Wegovy contains semaglutide, a medicine that works like GLP-1, a hormone your gut releases after you eat. It acts on the parts of the brain that control appetite, so you feel fuller and less hungry. How it is taken, the doses and what its licence covers are in what is Wegovy?, each dose step in our Wegovy dose schedule, and how the weeks usually go in how long Wegovy takes to work.
Is Wegovy approved in the UK, and what does that mean?
Yes. Wegovy has a UK marketing authorisation, the licence the MHRA grants once it has assessed a medicine's quality, safety and effectiveness and judged that, for the people it is licensed for, the benefits justify the risks. The MHRA's job is to make sure medicines work and are acceptably safe. A licence does not mean a medicine has no side effects, and it covers use as the product information describes: the right person, at the licensed doses, with the checks it asks for.
Who can have Wegovy through Solira
Treatment may be suitable if you're aged 18–85 and have a BMI of 30 or above, or a BMI of 27–29.9 alongside one of the following: high blood pressure, raised cholesterol or blood fats, obstructive sleep apnoea, cardiovascular disease, prediabetes, or type 2 diabetes.
The 7.2mg dose is for adults with a BMI of 30 or above only. Not sure of your BMI? Use our BMI calculator.
Who should not take Wegovy?
The UK product information gives one reason never to use Wegovy: an allergy to semaglutide or to any of its other ingredients. It should also not be used in pregnancy or while breastfeeding. Beyond that, it lists situations where Wegovy is not recommended, has not been studied, or needs extra care:
| If you | What the UK product information says |
|---|---|
| Are allergic to semaglutide or another ingredient | Do not use Wegovy |
| Are pregnant, trying for a baby or breastfeeding | Should not be used. Stop at least 2 months before a planned pregnancy |
| Have had pancreatitis | Not studied in people who have had it. Use with caution |
| Have gastroparesis (slow stomach emptying) | Stomach side effects may be more severe. Not recommended if it is severe |
| Have end-stage kidney disease | Not recommended |
| Have severe liver disease | Limited experience. Use with caution |
| Have severe heart failure (NYHA class 4) | No experience |
| Have diabetes and use insulin or a sulfonylurea | Higher risk of low blood sugar. The dose of those medicines may need lowering. Wegovy is never a substitute for insulin |
| Have diabetic eye disease | Needs close monitoring: a quick improvement in blood sugar can make it worse for a while |
| Have had weight loss surgery | A risk factor for low blood sugar. In the SELECT trial, 2 of 87 people with past weight loss surgery had serious low blood sugar on Wegovy, against none of 97 on placebo |
| Take warfarin or a similar blood thinner | More frequent INR blood tests when you start |
| Use another GLP-1 or semaglutide medicine, including Ozempic | Not to be used together |
| Are due an operation under general anaesthetic or deep sedation | Tell your surgical team: food or drink left in the stomach can reach the lungs |
| Are 85 or over | Limited experience |
Our consultation asks about each of the conditions below. If any of them applies to you, we cannot supply Wegovy through our service, and your GP is the right person to talk to:
- Cirrhosis or severe liver disease (liver failure, or told you are Child-Pugh C)
- Chronic kidney disease (eGFR < 30 mL/min)
- Heart failure that leaves you breathless at rest or unable to do any activity (NYHA class 4)
- History of pancreatitis
- Medullary thyroid cancer (MTC) or MEN-2, in you or a blood relative
- Currently having chemotherapy, immunotherapy or other active cancer treatment
- Type 1 diabetes
- An eating disorder diagnosed by a doctor, now or in the past (anorexia, bulimia, binge eating disorder)
- Gallbladder problems right now: gallstones causing pain, cholecystitis, or waiting for gallbladder surgery
- Gastroparesis (delayed stomach emptying) or a previous bowel obstruction
We also cannot supply Wegovy if you are pregnant, breastfeeding or trying for a baby, or if you take insulin or a sulfonylurea (such as gliclazide). GLP-1 treatment with insulin or a sulphonylurea can cause dangerously low blood sugar (hypoglycaemia). This needs to be managed by your GP or diabetes team, who can adjust your existing medicines at the same time.
Wondering whether Wegovy is suitable for you? Our consultation asks about your health and your medicines, and a GPhC-registered pharmacist reviews every answer before anything is supplied.
Check your eligibilityWhat are the common side effects of Wegovy?
Most Wegovy side effects are gut related, most often appear while your dose is going up, and settle as your body adjusts. The UK product information groups them by how often they happen. Altered skin sensation and hair loss may happen more often at the 7.2mg dose.
- Very commonmore than 1 in 10
- Commonup to 1 in 10
- Headache
- Nausea
- Vomiting
- Diarrhoea
- Constipation
- Stomach pain
- Tiredness
- Indigestion
- Reflux
- Burping
- Wind
- Bloating
- Dizziness
- Altered skin sensation
- Hair loss
- Gallstones
- Injection site reactions
In the four main trials in the UK product information, over 68 weeks on Wegovy 2.4mg, nausea affected 43.9% of people compared with 16.1% on placebo, diarrhoea 29.7% compared with 15.9%, vomiting 24.5% compared with 6.3%, and constipation 24.2% compared with 11.1%. Most of these were mild to moderate and short-lived, although constipation tended to last longer, and they were reported most often while the dose was being increased. Stomach side effects led 4.3% of people to stop treatment for good. How to manage each one is in our guide to Wegovy side effects, and the higher dose is covered in Wegovy 7.2mg.
What are the serious risks of Wegovy?
These are less common, but they are the ones to know the signs of. The frequencies are the UK product information's: uncommon means up to 1 in 100 people, rare up to 1 in 1,000, and very rare up to 1 in 10,000. The "When should you get help?" box below says exactly what to do.
| Risk | How common | Signs to look out for |
|---|---|---|
| Pancreatitis (inflamed pancreas) | Uncommon. Confirmed in 0.2% of people on 2.4mg in the main trials, against under 0.1% on placebo | Severe stomach pain that does not go away, which may spread to your back, with or without vomiting |
| Gallstones | Common. Reported in 1.6% of people on 2.4mg, and led to an inflamed gallbladder in 0.6% | Pain in the upper right of your tummy, fever, or yellowing of the skin or eyes |
| Dehydration, which can affect your kidneys | Vomiting and diarrhoea are very common. In rare cases the fluid loss makes kidney function worse | Dizziness, passing much less urine, a dry mouth |
| Kidney stones | Uncommon | Pain in your back or lower tummy, difficulty passing urine, or a change in its colour |
| Low blood sugar | Common in people with type 2 diabetes, uncommon in people without | Sweating, shaking, sudden hunger, confusion |
| Diabetic eye disease getting worse | Common in people with type 2 diabetes | Any change in your vision |
| NAION, a sudden loss of vision from the optic nerve | Very rare | Sudden, usually painless, loss of all or part of the vision in one eye |
| Stomach contents reaching the lungs during anaesthesia | Reported; no frequency given | Tell your surgical team you take Wegovy before any operation or sedation |
| Bowel obstruction | Not known (reports since the medicine came into use) | Severe constipation with stomach pain, bloating or being sick |
| Low blood pressure, or a higher heart rate | Uncommon. Heart rate rose by 3 beats a minute on average in the main trials | Light-headedness when you stand, or a racing heartbeat at rest |
| Severe allergic reaction | Rare | Swelling of the face, lips or throat, difficulty breathing, or a widespread rash. Call 999 |
| Hip fracture | Rare | In SELECT, hip and pelvis fractures were reported more often on Wegovy than on placebo in women (1.0% against 0.2%) and in people aged 75 or over (2.4% against 0.6%) |
In January 2026 the MHRA strengthened its warning on pancreatitis: there have been rare reports of severe (necrotising) and fatal pancreatitis with GLP-1 medicines. If pancreatitis is suspected, Wegovy is stopped, and if it is confirmed, Wegovy must not be started again.
Can Wegovy affect your eyesight?
Very rarely. NAION (non-arteritic anterior ischaemic optic neuropathy) happens when the blood supply to the front of the optic nerve drops, and it causes a sudden, usually painless, loss of vision, typically in one eye. In June 2025 the European Medicines Agency's safety committee concluded that NAION is a very rare side effect of semaglutide, affecting up to 1 in 10,000 people taking it. In large studies of adults with type 2 diabetes, semaglutide was linked to roughly twice the risk, which works out at about one extra case for every 10,000 people treated for a year.
The MHRA issued its own warning in February 2026. It noted that the UK Yellow Card scheme had received three reports suggestive of NAION with semaglutide up to 1 August 2025, while it estimated that roughly 10.2 million packs of semaglutide had been dispensed in the past five years, and that a report does not prove the medicine caused the problem. Its advice: if your eyesight suddenly gets worse in one or both eyes, go to eye casualty, where there is one in your area, or A&E urgently. If NAION is confirmed, semaglutide is stopped. The warning covers every semaglutide medicine, which is why it named Wegovy, Ozempic and Rybelsus together.
Is it safe to have an operation while on Wegovy?
Before any operation: tell your surgical or anaesthetic team you take a GLP-1 medicine. It slows stomach emptying, which matters for anaesthesia.
The MHRA explains why: with a slower-emptying stomach, food and drink can still be in your stomach after the usual fasting time, and during a general anaesthetic or deep sedation it could reach your airways and lungs. Your anaesthetist may change your instructions before the procedure. Keep taking the medicine you already have as usual, unless your surgical or anaesthetic team tells you otherwise.
Does Wegovy cause depression or suicidal thoughts?
The evidence does not support a link. In July 2023, reports of suicidal thoughts in people using semaglutide and liraglutide, another GLP-1 medicine, started a European review. In April 2024 the European Medicines Agency's safety committee concluded that the available evidence does not support a causal association between GLP-1 medicines, semaglutide included, and suicidal or self-injurious thoughts and actions. In September 2024 the MHRA reached the same conclusion from the UK data, including for depression, and said it will keep monitoring new data.
That does not mean your mood does not matter. Tell your pharmacist in your consultation about any history of depression or another mental health condition, and tell us if your mood changes during treatment. If you have thoughts of harming yourself, on any medicine, get help straight away. Call 999 or go to A and E if you feel unsafe, or call the Samaritans free on 116 123 at any time. Our guide to whether Mounjaro can cause depression covers the evidence across GLP-1 medicines.
Is Wegovy safe in pregnancy, and does it affect the pill?
Wegovy must not be used in pregnancy. Animal studies showed harm to the unborn young and there is little information from pregnant women, so the product information recommends contraception while you take it. This is the counselling every Wegovy patient receives from us:
Pregnancy: these medicines must not be used in pregnancy. Stop and contact us or your GP immediately if you become pregnant. If planning pregnancy: stop Mounjaro at least 1 month before, Wegovy at least 2 months before.
The pill: Wegovy needs no extra precautions unless severe vomiting or diarrhoea occurs, then follow missed-pill guidance.
Wegovy should also not be used while breastfeeding, and we do not supply it to anyone who is. Mounjaro and Foundayo are different: they can make the pill less reliable for a while. Everything, medicine by medicine, is in our guide to contraception and pregnancy on GLP-1 treatment, and the questions women ask us most are gathered on our page on women's health on weight loss treatment.
Is Wegovy safe long term?
Semaglutide has been licensed in the UK since 2018, first for type 2 diabetes. The longest Wegovy trial, SELECT, followed people for an average of 39.8 months. These are the main trials:
| Trial | Who took part | How long | What it found on safety |
|---|---|---|---|
| STEP 1 (New England Journal of Medicine, 2021) | 1,961 adults with overweight or obesity, without diabetes | 68 weeks | Nausea and diarrhoea were the most common side effects, usually mild to moderate and easing with time. 4.5% stopped because of stomach side effects, against 0.8% on placebo |
| STEP 5 (Nature Medicine, 2022) | 304 adults with overweight or obesity, without diabetes | 104 weeks (2 years) | Stomach and bowel side effects, mostly mild to moderate, were reported by 82.2% on Wegovy and 53.9% on placebo |
| SELECT (New England Journal of Medicine, 2023) | 17,604 adults aged 45 or over with established cardiovascular disease, a BMI of 27 or above and no diabetes | An average of 39.8 months | 16.6% stopped Wegovy because of a side effect, against 8.2% on placebo |
SELECT was designed to look at the heart. Over the trial, 6.5% of people on Wegovy 2.4mg had a heart attack or stroke or died from cardiovascular causes, compared with 8.0% on placebo. Individual results vary. Our guide to Wegovy vs Ozempic has more on the heart trials of both medicines.
Semaglutide stays in your body for about 7 weeks after the last 2.4mg dose, which is why it is stopped at least 2 months before a planned pregnancy. What happens to your weight if you stop matters too. The counselling we give every patient is:
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 Wegovy the same as Ozempic?
They contain the same medicine, semaglutide, made by the same company, Novo Nordisk, but they are different products with different licences. Ozempic is licensed for type 2 diabetes, at weekly doses from 0.25mg up to 2mg. Wegovy is licensed for weight management, at weekly doses up to 2.4mg, or 7.2mg for adults with a BMI of 30 or above. Ozempic is not licensed for weight loss.
Because the medicine is the same, so are the safety warnings, from pancreatitis to NAION. Two practical rules follow from the product information and the MHRA: never use two semaglutide or GLP-1 medicines together, and speak to a healthcare professional before switching between them, even between brands of the same medicine. Our full comparison is in Wegovy vs Ozempic. For the other weekly injection we supply, read our guide Is Mounjaro safe?
Is it safe to buy Wegovy online? Fake pens and semaglutide vials
Wegovy from a registered UK pharmacy, after a consultation, is the licensed medicine described in this guide. Wegovy or "semaglutide" bought anywhere else may not be. The MHRA has had reports of people having severe side effects from fake GLP-1 medicines, and warns that illegally sold weight loss products may be fake, contaminated, wrongly dosed or contain ingredients not on the label. More on spotting a genuine medicine is on our safety page.
A powder in a vial is never Wegovy. The MHRA says genuine GLP-1 medicines come as pre-filled pens or tablets. Semaglutide sold as a powder that you mix with liquid before injecting is not an authorised product.
Fake pens can look real. The MHRA has had reports of counterfeit pre-filled pens that closely copy the licensed ones, so how a pen looks is not proof that it is genuine. Where it came from is what matters.
Check the pharmacy. Selling these medicines through salons or social media, or without a consultation, is against the law. Any pharmacy in Great Britain can be checked on the General Pharmaceutical Council's register: QuickCare Pharmacy, the registered pharmacy that dispenses for Solira, is number 9013213.
Not sure about a pen? Do not use it. Keep it, message us, and report it on the MHRA Yellow Card website, which takes reports of suspected fake medicines as well as side effects.
How does our pharmacist check Wegovy is safe for you?
Your consultation. You tell us about your health, your medicines and your weight.
A pharmacist review. A GPhC-registered pharmacist reviews every answer, and nothing is supplied until they approve it.
A check before every reorder. You answer a short health check before each reorder, and your pharmacist reviews you before each dose increase, so a new condition, medicine or side effect is picked up.
Support while you are on treatment. Message your pharmacist through your account about any side effect. A slower dose increase is often possible, and stopping is not the only option.
What does the black triangle on Wegovy mean?
The black triangle (▼) on Wegovy's leaflet and product information means it is under additional monitoring, so that new safety information can be identified quickly. The MHRA says it does not mean the medicine is unsafe. You can help by reporting any suspected side effect, or a medicine you think may not be genuine, on the MHRA Yellow Card website or app. Tell your pharmacist about any side effect that worries you as well.