Wegovy pens (semaglutide) for weight management

What is Wegovy?

Wegovy is a once-weekly injection containing semaglutide. In the UK it's licensed for weight management in adults with a BMI of 30 or more, or 27 to 29.9 with at least one weight-related health condition, alongside a reduced-calorie diet and more physical activity.¹

It's the same medicine as Ozempic and Rybelsus, which are used to treat type 2 diabetes.¹⁰ Wegovy's licence also covers lowering the risk of heart attack, stroke or death from heart disease in adults who already have heart or circulation disease and a BMI of 27 or more, teenagers aged 12 and over with obesity, and a type of fatty liver disease called MASH.¹ We only prescribe it for weight management in adults.

The FlexTouch pen comes in five strengths: 0.25mg, 0.5mg, 1mg, 1.7mg and 2.4mg. Each pen holds four weekly doses and comes with four needles.³ A 7.2mg dose is also licensed for adults with obesity. It comes in a different pen that's used once and thrown away.²

Does Wegovy work for weight loss?

For most people, yes. The main trial, STEP 1, gave 1,961 adults without diabetes either Wegovy 2.4mg or a dummy injection (placebo) for 68 weeks, alongside diet and activity support. Average weight loss was 14.9% on Wegovy against 2.4% on placebo.¹³

The average hides a wide spread. About a third of people on Wegovy (30.2%) lost 20% or more of their weight, while around 1 in 6 (16.5%) lost less than 5%.¹ The trial was funded by Novo Nordisk, which makes Wegovy.

The 7.2mg dose was tested in STEP UP, in 1,407 adults without diabetes over 72 weeks. Average weight loss was 18.7% on 7.2mg, 15.6% on 2.4mg and 3.9% on placebo.¹⁵ That trial was also funded by Novo Nordisk. Whether a higher dose is right for you is the prescriber's decision.

Wegovy has also been tested on heart outcomes. SELECT followed 17,604 adults aged 45 and over who had heart or circulation disease and a BMI of 27 or more, but not diabetes, for an average of 39.8 months. A heart attack, stroke or death from heart disease happened to 6.5% of people on Wegovy and 8.0% on placebo.¹⁶ That's a 20% lower relative risk, or about 1.5 fewer events for every 100 people treated over roughly three years. SELECT was funded by Novo Nordisk.

What happens if you stop Wegovy?

Most of the weight tends to come back. In the STEP 1 extension, 327 people were followed for a year after their treatment and lifestyle support stopped at week 68. They regained about two thirds of the weight they had lost, and most of the improvements in things like blood pressure and blood sugar drifted back towards where they started.¹⁴

A year after stopping, they were still an average of 5.6% lighter than when they began.¹⁴ The study was funded by Novo Nordisk.

It's worth knowing before you start: Wegovy works while you're taking it, so any decision to stop is one to plan with your prescriber.

How does Wegovy work?

Semaglutide copies GLP-1, a hormone your gut releases after eating. It helps you feel fuller and less hungry, and it slows down how quickly your stomach empties.⁴⁸

It also lowers blood sugar, which is why the same medicine is used for type 2 diabetes. The risk of a hypo goes up if you also take insulin or a sulfonylurea, and the dose of those may need lowering.³

How to get Wegovy on prescription in the UK

On the NHS, NICE recommends Wegovy within specialist weight management services, for up to 2 years, for adults with at least one weight-related condition and a BMI of 35 or more, or 30 to 34.9 if they meet the criteria for a specialist referral. Lower BMI thresholds are used for people from some ethnic backgrounds.⁹ Your GP can tell you whether a referral is an option.

Privately, a healthcare professional has to assess you before a prescription can be issued.⁴ With us, that works like this:

1. You answer our online questions about your health, your weight history and any medicines you take.
2. We confirm your weight independently, by video call or from a recent weight recorded by your GP. Pharmacies that prescribe at a distance have to verify it rather than take it on trust.¹¹
3. With your consent, our prescriber checks your Summary Care Record, and we let your GP know what we've prescribed.
4. If Wegovy is suitable, we dispense it and post it in plain packaging.

If a seller doesn't ask these questions, treat that as a warning sign. The MHRA advises against buying these medicines from unregulated sellers such as beauty salons or through social media.⁴

Who can use our Wegovy service?

This service is for adults whose weight is in the range Wegovy is licensed for, and who can be looked after safely at a distance.

This service may be suitable if

• You're aged 18 to 65.
• Your BMI is 30 or more, or 27 to 29.9 with a weight-related condition such as high blood pressure, high cholesterol, prediabetes, type 2 diabetes, sleep apnoea or heart disease.¹
• You're registered with a UK GP and happy for us to contact them.
• You're already using a weight loss medicine and want to carry on with us. We'll ask for your current dose, when you last injected and where it came from.

We can't prescribe Wegovy if

• You're pregnant, breastfeeding, having IVF, or planning a pregnancy in the next 3 months.
• You have type 1 diabetes.
• You've ever had pancreatitis.
• You or a close relative have had medullary thyroid cancer or MEN2.
• You currently have an eating disorder.
• You'd be using it at the same time as another GLP-1 medicine, such as Mounjaro, Ozempic or Saxenda.³

Some of these are stricter than the licence. They're the rules for our online service.

Tell our prescriber before treatment if

• You have type 2 diabetes, especially if you use insulin or a sulfonylurea such as gliclazide.³
• You have diabetic eye disease (retinopathy).¹
• You have gastroparesis or another long-term stomach or bowel condition.³
• You've had gallstones or other gallbladder problems.¹
• You have kidney or liver problems.
• You take warfarin or a similar blood thinner.³
• You have an operation or a procedure under sedation coming up.⁸
• You've had an eating disorder in the past, or you have depression or another mental health condition.

Wegovy results: when can changes appear?

Give it a proper run. The dose goes up every 4 weeks, so you won't reach the usual 2.4mg dose until week 17.¹ The early doses are mainly there to let your body get used to it.

The licence says that if you haven't lost at least 5% of your starting weight after 6 months, the prescriber should decide whether it's worth carrying on.¹ NICE uses the same check for NHS patients.⁹

Weigh yourself once a week, on the same scales at the same time of day, so you're comparing like with like.

Does Wegovy make you feel sick?

It often does at first. In the trials of the 2.4mg dose, 43.9% of people had nausea, 29.7% diarrhoea, 24.5% vomiting and 24.2% constipation.² In STEP 1 these were usually mild to moderate and eased with time, but 4.5% of people stopped Wegovy because of them.¹³

If sickness is making it hard to eat or drink, do not push on to the next dose increase. Talk to us first. The licence lets the prescriber delay an increase, or step you back to the previous dose until things settle.¹

It's best not to drink alcohol on Wegovy, because it can make feeling or being sick worse.¹⁰

Our guide, Feeling sick on Mounjaro or Wegovy: when to hold your dose, goes through what helps, what to do if you're being sick, and when it's time to get help.

How to use Wegovy pens

The schedule comes from the Wegovy licence.¹ Your prescriber may keep you on a dose for longer.

• Inject once a week, on the same day each week if you can, at any time of day, with or without food.³
• Inject under the skin of your stomach, thighs or upper arms, using a new needle each time.³
• You can change your injection day, as long as it's been at least 3 days since your last injection.³
• If you miss a dose and it's 5 days or less since you should have taken it, take it as soon as you remember. If it's more than 5 days, skip it and take your next dose on your usual day. Do not take a double dose.³
• Each FlexTouch pen holds four doses. There will be a little medicine left after the fourth, but not enough for another dose, so throw the pen away rather than trying to get it out.¹⁴
• Do not change your dose or stop without talking to us first.

The leaflet in the pack has step-by-step pictures for using the pen. Read it before your first injection.³

Storing your pens. Keep new pens in the fridge at 2°C to 8°C, away from the cooling element, and never freeze them. Once you've started a FlexTouch pen, you can keep it for up to 6 weeks below 30°C or in the fridge, with the cap on to protect it from light.¹ The single-use 7.2mg pens can be kept out of the fridge, at no more than 30°C, for up to 28 days.²

Side effects of Wegovy

Reported side effects

Very common (more than 1 in 10 people): feeling sick, being sick, diarrhoea, constipation, stomach pain, headache and tiredness.¹

Common (up to 1 in 10 people): dizziness, changes in taste, changes in skin sensation such as tingling, indigestion, gastritis, reflux, burping, wind, bloating, gallstones, hair loss and injection site reactions. In people with type 2 diabetes, low blood sugar and worsening diabetic eye disease are also common.¹

Changes in skin sensation were much more frequent on 7.2mg: 21.6% of people in STEP UP, against 0.3% on placebo. Most were mild to moderate and settled while people stayed on treatment.²

The licence says hair loss was mostly mild, most people recovered while staying on treatment, and it was reported more often in people who lost 20% or more of their weight.¹ Our guide, Mounjaro, Wegovy and hair loss, explains what the evidence shows and what helps.

When to stop and get help

Most side effects aren't a reason to worry. These are.

Call 999 or go to A&E if you have:

1. Swelling of your face, lips, tongue or throat, difficulty swallowing or breathing problems. This could be a severe allergic reaction, which is rare.³
2. Severe stomach pain that won't go away, which may spread to your back and come with feeling or being sick. This can be a sign of pancreatitis. In January 2026 the MHRA strengthened its warning after rare severe and fatal cases with these medicines.⁵
3. Sudden loss of vision in one eye. Go to eye casualty if there's one near you, or A&E. This can be a sign of NAION, a rare eye condition that may affect up to 1 in 10,000 people taking semaglutide.⁶⁷

Get advice the same day if you can't keep fluids down, or you're losing a lot of fluid through vomiting or diarrhoea. Severe dehydration can affect your kidneys.¹⁴

These symptoms don't always mean something serious is wrong, but they need checking. You can report any side effect to the MHRA Yellow Card scheme.¹²

The MHRA has also looked at reports of depression and suicidal thoughts with GLP-1 medicines. It says the evidence doesn't support a causal link, and it's still monitoring.⁴ Tell us if your mood changes.

Pregnancy, contraception and breastfeeding

Pregnancy. Do not use Wegovy if you're pregnant. If you're planning a pregnancy, stop it at least 2 months before, because it stays in your body for a long time.¹⁴ If you get pregnant while using it, stop and speak to us or your GP straight away.⁴

The pill. Wegovy isn't expected to make the pill less effective.¹ Being sick or having bad diarrhoea can stop the pill being absorbed, though, so follow your pill leaflet's advice if that happens.

Breastfeeding. Wegovy shouldn't be used while you're breastfeeding.²⁴

Wegovy, operations and other medicines

Because Wegovy slows down how quickly your stomach empties, there's a possible risk of stomach contents getting into your lungs under a general anaesthetic or deep sedation. If you're having an operation or a procedure such as an endoscopy, tell the team, including the anaesthetist, that you use Wegovy. Do not stop it without discussing it with them first.⁸

Tell us about every medicine you take, including ones you buy. In particular:

• insulin or a sulfonylurea, as the risk of low blood sugar goes up. Signs include a cold sweat, shaking, a fast heartbeat, and feeling very hungry, anxious or confused.³
• warfarin or a similar blood thinner, as you may need more frequent blood tests when you start.³
• any other GLP-1 medicine, which shouldn't be used at the same time.³

If you're thinking of switching between Wegovy and another weight loss medicine, speak to a prescriber first. The MHRA warns that switching without advice can make side effects more likely or the treatment less effective.⁴

How do Wegovy and Mounjaro compare?

The only head-to-head trial so far, SURMOUNT-5, gave 751 adults with obesity but not type 2 diabetes the highest dose of either medicine they could manage for 72 weeks. Average weight loss was 20.2% on Mounjaro and 13.7% on Wegovy.¹⁷ People knew which medicine they were taking, and the trial was funded by Eli Lilly, which makes Mounjaro.

That's a real difference, but it isn't the whole story. Wegovy is the one licensed to lower the risk of heart attack and stroke in people with heart or circulation disease.¹ Our guide, Wegovy vs Mounjaro: which is better for weight loss?, goes through the evidence and when Wegovy might still be the better fit.

Support after you start

Wegovy is a long-term treatment, and you can come back to us with questions at any point.

• If sickness, diarrhoea or constipation is getting in the way of eating and drinking, tell us rather than waiting for your next order.
• Tell us before your next order if you've started a new medicine, have an operation coming up or are planning a pregnancy.
• Do not increase, lower or stop your dose on your own. Ask us and the prescriber will advise.
• If something doesn't feel right, get in touch. Our pharmacists are happy to talk it through.

Wegovy FAQs

• Can I buy Wegovy without a prescription?

  No. Wegovy is a prescription-only medicine, so a prescriber has to assess you before it can be supplied. The MHRA warns against buying it from anyone who skips that step.⁴

• Can I get Wegovy on the NHS?

  Sometimes. NICE recommends it within specialist weight management services, mainly for adults with a BMI of 35 or more and a weight-related condition, for up to 2 years.⁹ Your GP can tell you whether you'd be referred.

• How much weight will I lose on Wegovy?

  Nobody can tell you that in advance. In STEP 1 the average was 14.9% over 68 weeks, against 2.4% on placebo, but around 1 in 6 people lost less than 5%.¹¹³

• When will I notice a difference?

  Usually not in the first few weeks. The dose is built up over 16 weeks, and the licence says to review whether it's worth continuing if you haven't lost at least 5% after 6 months.¹

• What happens if I miss a dose?

  If it's 5 days or less since your usual day, take it as soon as you remember. If it's more than 5 days, skip it and carry on from your next usual day. Do not take a double dose.³

• Can I drink alcohol on Wegovy?

  It's best not to. Alcohol can make feeling or being sick worse.¹⁰

• Does Wegovy cause hair loss?

  It can. Hair loss is a listed common side effect, mostly mild, and most people in the trials recovered while staying on treatment.¹ Our guide to hair loss on Mounjaro and Wegovy explains what's happening and what helps.

• Do I need to stop Wegovy before an operation?

  Do not stop it on your own. Tell the team doing the operation, including the anaesthetist, that you use Wegovy, and follow their advice.⁸

• Is Wegovy the same as Ozempic?

  Same medicine, different licence. Both contain semaglutide, but Ozempic is used for type 2 diabetes and Wegovy for weight management.¹⁰

• How should I store Wegovy?

  In the fridge until you start a pen, and never frozen. Once you've started a FlexTouch pen, you can keep it below 30°C or in the fridge for up to 6 weeks.¹

• What happens when I stop Wegovy?

  Most people put a lot of the weight back on. In the STEP 1 extension, people regained about two thirds of what they'd lost within a year of stopping.¹⁴ Plan any stop with your prescriber.

• Can I switch from Mounjaro to Wegovy?

  Yes, but not on your own. Speak to a prescriber first, as switching without advice can make side effects more likely or the treatment less effective.⁴ We'll ask for your current dose and when you last injected.