What are Wegovy (Semaglutide) weight loss injections?

Dr. Babak Ashrafi

Medically reviewed by

Dr Babak Ashrafi

Last reviewed: 13 Sep 2023

Wegovy weight loss injections are a prescription weight loss treatment that is available to order online from ZAVA. They can help reduce your appetite, making it easier to lose weight as part of a diet and exercise plan.

Dr. Babak Ashrafi

“Wegovy is a medication adapted from an existing weight loss treatment, Ozempic (semaglutide). It’s useful for people who need help losing weight as part of an overall weight management plan. This is why we’ve added Wegovy to our weight loss service.”

Dr Babak Ashrafi, Clinical Lead for Service Expansion at ZAVA

What is Wegovy?

The Wegovy weight loss medication is new to the UK and became available in Sept 2023. Adapted from a similar treatment for diabetes, Ozempic, Wegovy works in the same way but is available for people without diabetes.


  • is a weight loss treatment
  • works by reducing your appetite to stop you from overeating
  • is an injection used once a week
  • is a prescription-only medication
  • is for people with a BMI of over 30, or over 27 in some cases
  • is effective in over 80% of users
  • can lead to weight loss of over 20%
  • is safe to use if prescribed by a doctor

Wegovy is a prescription-only weight loss injection treatment for people who are overweight. The active ingredient in Wegovy is a man-made hormone called semaglutide. It works by reducing your appetite like your hormones do naturally, making weight loss easier as you are less hungry while you diet.

What is Wegovy used for

Wegovy medication is a weight loss treatment for people who are overweight. This means someone who has a BMI of over 30, or over 27 if they have a weight-related health problem. A doctor can’t prescribe Wegovy for weight loss to someone who doesn’t meet these criteria, even if they want to lose weight anyway.

Can I get Wegovy without a prescription?

No. Wegovy is a prescription medication because a doctor needs to make sure it’s safe and likely to be effective for you to use. You can’t buy Wegovy over-the-counter or buy Wegovy online legally without a doctor being involved.

ZAVA can help you find out if you can be prescribed Wegovy by doing an assessment when you place your order. Getting a Wegovy prescription online from a regulated service means being assessed to the same criteria used for getting a prescription in person.

How to use a Wegovy pen

Wegovy pens only need to be used once a week for them to be effective and work best as part of a weight loss plan that includes diet and exercise. If you’re prescribed Wegovy, you’ll start on a lower dose for your first month and it will be increased each month afterwards, until month 5 of your treatment (see available dosages section below for more details).

How to inject Wegovy

Before starting treatment, carefully read the instructions in the patient information leaflet that comes with Wegovy and follow any instructions from your doctor. When you’re ready to try your first dose, follow the steps below:

  1. Wash your hands.
  2. Decide on where you want to inject your first dose. You can choose from your lower abdomen, thigh, or upper arm. Once you’ve decided, wash the area you’re going to inject with an alcohol swab or soap and water.
  3. Check the name and dose of your pen to make sure it contains your prescribed dose of Wegovy. Look through the pen window to ensure the liquid is clear and colourless.
  4. Remove the pen cap and push a new needle onto the pen. Turn the needle until it is tight. Pull off the outer and inner needle caps when ready to inject or check the flow. Check the flow with each new pen. You do not need to check the flow every time you inject, only the first time you use a new pen. Each pen will provide you with 4 weekly doses when used correctly.
  5. Turn the dose selector until the dose counter stops, and it shows your prescribed dose.
  6. Insert the needle into your skin. Ensure you can see the dose counter.
  7. Press and hold down the dose button until the dose counter shows 0. Keep pressing the dose button with the needle in your skin and slowly count to 6.
  8. Remove the needle from your skin. Carefully place the outer needle cap onto the needle, before removing the needle from the pen and disposing of it in a sharps bin.
  9. Place the pen cap back onto the pen and store out of sight and reach of children. The pen can be stored at a temperature below 30°C or refrigerator (2°C to 8°C) away from the cooling element.
wegovy injection sites

Some extra advice:

  • Store your injections in the fridge.
  • Check your pen before using it in case it’s been broken.
  • Avoid injecting into areas that are bruised, sore, hard, or scarred. Also, be careful not to inject into your muscles or veins.
  • Don’t touch the needle cover to avoid accidentally pricking yourself.
  • Don’t try and stop the injection halfway through because the needle locks once it starts.
  • Make sure you switch up where you inject your Wegovy after each dose.

What is the best time of day to use Wegovy

You can take Wegovy any time of day, with or without food. As long as you remember to take it on the same day at around the same time every week, you can decide for yourself when taking your Wegovy works best for you.

Before driving

You can drive on Wegovy, but it’s a good idea to pay attention to how you feel after your first few doses to make sure Wegovy doesn’t affect your ability to drive safely.

Wegovy missed doses

If you miss a dose by less than 5 days, you can take that dose, and then your next one will be a week after this delayed dose.

If you miss a dose and it’s more than 5 days, then wait (i.e. skip this dose) and take your next dose on the usual day, at the usual time.

If you want to change the day of the week you use Wegovy to better suit your needs, you can do so as long as there are more than 3 days between doses.

If the last dose you took was more than 2 weeks ago, you need to restart at the lowest strength dose of 0.25mg weekly, and start again.

What happens when you stop taking Wegovy?

Shortly after you stop your Wegovy treatment, your appetite will increase back to normal levels. This is important to keep in mind when you’re trying to maintain your new weight, but if you continue to stick to your diet and exercise plan you can avoid putting the weight back on.

Wegovy and alcohol: Can You Drink Alcohol On Wegovy® (Semaglutide)?

Alcohol doesn’t react with Wegovy, but since they both lower your blood sugar, you should watch out for dizziness. Plus, alcohol has a lot of extra calories and can increase your appetite for unhealthy foods. So if you can, try to drink less during treatment.

How does Wegovy work

The active ingredient in Wegovy is semaglutide. Semaglutide is an artificial version of something your body already uses to manage appetite. It works by reducing your appetite, just like your body naturally does after you’ve eaten. This is how Wegovy helps you feel full after eating less food than normal and helps you avoid overeating or snacking, making it easier to stick to your diet plan.

How quickly does Wegovy work?

After you start treatment, you should feel fuller after eating by the second or third dose. But since people react differently to medications, it might work slightly faster or slower for you. If you don’t see any change in your appetite after 6 weeks, you might want to think about changing treatment to an alternative like Saxenda or Ozempic.

When it comes to Wegovy weight loss results, it really depends on a person’s individual circumstances and how well they stick to their diet and exercise plan. You may see weight loss after just 12 weeks or it may take longer.

Available Wegovy dosages

There are 5 different Wegovy dosages. They refer to the semaglutide dosage to be taken with each injection:

  • 0.25mg
  • 0.5mg
  • 1mg
  • 1.7mg
  • 2.4mg

You’ll be started on the lowest dose in the first month and move up to the highest dose after 5 months. Each dose step takes at least 4 weeks before moving on to the next one.

A doctor can’t prescribe more Wegovy than is safe to use, so there aren’t higher doses to choose from. Wegovy is an effective treatment at the normal doses listed above, when used properly.

If you are prescribed Wegovy, your doctor will give you clear instructions on how to get the best and safest treatment possible. Wegovy can take up to 2 months to leave your system completely after your last dose.

wegovy dosage chart

How effective is Wegovy

Wegovy works for the majority of people who use it. Over 80% of Wegovy users can expect to see extra weight loss beyond what they would have achieved without it. You could lose 20% or more weight on this treatment.

We know this is true because of a 68-week long study done on patients using Wegovy. Compared to people just using a placebo (taking injections that don’t actually have medication in), this study showed that:

  • 86% lost at least 5% weight
  • 69% lost at least 10% weight
  • 50% lost at least 15% weight

What are Wegovy reviews like?

Wegovy is rated:

Comparison of Wegovy alternatives

Saxenda vs Wegovy

Saxenda works in almost exactly the same way as Wegovy. The only real difference is the active ingredient in Saxenda is another artificial hormone, liraglutide. But, both medications still work in the same way, which is by reducing your appetite.

You could try either Wegovy or Saxenda first. If you don’t find the treatment is working for you after 6 weeks, you could think about switching from Saxenda to Wegovy. People react differently to different medications so even though they’re similar, one could work when the other doesn’t. It’s impossible to tell which one will work for you, so the only way to know for sure is by trying them out.

Don’t ever take these medications together. If you want to switch from one to the other, get a doctor involved who can help you plan the switch so you don’t end up with both medications in your system at the same time. When switching from semaglutide (Wegovy or Ozempic) to Saxenda, you need to wait 2 months from the time of your last dose before you can start Saxenda. This is to reduce your risk of side effects.

Wegovy vs Ozempic

Ozempic is another name for semaglutide, but it is not licensed for weight loss. Wegovy is meant for patients with or without diabetes for weight loss, but Ozempic is only meant to treat people with type 2 diabetes. The active ingredient in both medications is the same, but the dosages can be different. Ozempic is available in 0.5mg, 1mg, or 2mg doses.

Other medical weight loss treatments

Other options to think about are:

  • Mysimba (tablets), similar to Wegovy and Saxenda, it reduces appetite as well
  • Xenical (tablets), a medication that stops your body from absorbing fat that you eat
  • Orlistat (tablets), the generic version of Xenical which works in the same way but cost less because it’s not branded
  • Alli (tablets), a version of orlistat
  • Weight loss surgeries, like stomach stapling

Other weight loss options

Weight loss options that don’t include medical treatments are always a good idea, and they usually can (and should) be used alongside any medical weight loss treatments you’re on. These can include:

  • dieting
  • exercising more
  • joining weight loss groups

Safety information

Wegovy should be safe for you to take as long as a doctor has prescribed it for you. Wegovy isn’t right for everyone, which is why a doctor won’t prescribe certain treatments if:

  • you’re pregnant or planning to get pregnant
  • you’re seriously allergic to any of Wegovy’s ingredients
  • you have a family history of MTC thyroid cancer (medullary thyroid carcinoma)
  • you have multiple endocrine neoplasia syndrome type 2

In order to make sure Wegovy is safe for you, a doctor will ask about:

  • any pancreas or heart problems
  • whether you’re pregnant, planning to become pregnant or breastfeeding

All of these questions are covered in ZAVA’s online assessment for Wegovy treatment.

Possible Wegovy side effects

Like any medication, Wegovy can cause side effects in some people.

Very common Wegovy side effects that affect more than 10% of users include:

  • headache
  • feeling sick
  • throwing up
  • diarrhoea
  • constipation
  • stomach pain
  • feeling weak or tired

Common side effects that affect up to 10% of users include:

  • dizziness
  • stomach and digestion problems
  • burping
  • gas
  • bloating
  • inflamed stomach
  • acid reflux
  • gallstone
  • hair loss
  • reactions where the injection was used
  • low blood sugar for people with diabetes

Uncommon side effects that affect up to 1% of users include:

  • fast heartbeat
  • increased pancreatic enzymes in blood tests

Signs of serious side effects and what to do

Stop using Wegovy and contact a doctor if you experiences any of the following:

  • severe stomach pain that doesn’t go away, even if you throw up
  • signs of gallbladder problems, including pain in the upper abdomen, fever, yellow skin or eyes, or clay-coloured poo
  • signs of low blood sugar, if you have type 2 diabetes, including dizziness or light-headedness, sweating, shakiness, blurred vision, slurred speech, weakness, anxiety, hunger, headache, feeling irritable or mood swings, confusion or drowsiness, fast heartbeat, or feeling jittery
  • kidney problems
  • changes to your eyesight, if you have type 2 diabetes
  • increased heart rate
  • depression or suicidal thoughts

For full safety information on Wegovy, please see this medication guide.

Frequently asked questions

Is Wegovy available in the UK?

Yes, Wegovy is available in the UK now. It is manufactured by Novo Nordisk.

Where can you buy Wegovy online?

If you have a prescription, you should be able to get it filled at most pharmacies. You are also able to buy Wegovy online using an online doctor service, like ZAVA.

How much does Wegovy cost?

For the lowest dose the price for Wegovy is £179.00.

Is it available on the NHS?

Yes, Wegovy is available on the NHS. Like Saxenda, Wegovy will only be prescribed by a weight management specialist if:

  • you’ve tried weight loss without medication first
  • you’ve tried treatments like orlistat first
  • weight loss surgery isn’t possible for you
  • you’ve a BMI of between 30 kg/m² and 35 kg/m² and a health problem that can affect your weight, such as diabetes
  • you’ve a BMI of 35 kg/m² or more, even if you do not have a weight related medical condition

Is it available with a private prescription?

Yes, it is possible to get a private prescription for Wegovy. Whether you can get it on private health insurance will depend on your insurance provider. ZAVA is able to offer Wegovy through its online doctor service.

What pharmacy has Wegovy in stock?

Wegovy stock is currently limited since it’s just been released in the UK. Pharmacies may have stock intermittently until the supply stabilises. The only way to know for sure is to check regularly. ZAVA will be posting stock updates as they are available, so please check back often.

How long does Wegovy stay in system

It takes up to 2 months for Wegovy to completely leave your system. 7 days after your last dose, 50% of the Wegovy from that dose will have been removed from your body. It takes much longer for your body to remove Wegovy completely.

Medically reviewed by:
Dr Babak Ashrafi Clinical Lead for Service Expansion

Babak studied medicine at King’s College London and graduated in 2003, having also gained a bachelor’s degree in Physiology during his time there. He completed his general practice (GP) training in East London, where he worked for a number of years as a partner at a large inner-city GP practice. He completed the Royal College of GPs membership exam in 2007.

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Last reviewed: 13 Sep 2023

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