Wegovy is a popular weight loss injection for overweight or obese adults, and is a brand-name for a medication called semaglutide. Wegovy reduces your appetite, helping you lose weight alongside a healthy diet and regular exercise. It’s an effective weight loss medication, and on average can help you lose up to 15% of your starting body weight after 68 weeks on the highest maintenance dose.

Wegovy is suitable if you have a body mass index (BMI) of over 30, or over 27 and a weight-related medical condition or risk factor, such as high blood pressure. If you’re not sure if you’re eligible for Wegovy, you can use our BMI calculator to check.

Wegovy, which is a brand name of semaglutide, works by mimicking a naturally occurring hormone called glucagon-like peptide-1 (GLP-1). This hormone helps to regulate your blood sugar levels, and also sends signals to receptors in your brain that manage your appetite. Wegovy works for weight loss by reducing your appetite, so you do not need to eat as many calories to feel full. It can also delay how quickly food empties out of your stomach, so you’ll feel fuller for longer than before.

Wegovy is prescribed alongside a complementary diet and exercise plan to help you with your weight loss journey. While Wegovy is a highly effective weight loss medication, it's most effective when combined with other weight loss strategies.

How long does Wegovy take to work?

Wegovy starts working straight away, and most patients start feeling fuller within the first few days of taking it. You should start seeing noticeable improvements to your weight within 5-6 weeks. Speak to your doctor if you don’t see any weight loss results within 6 months of taking Wegovy, as it may not be the right option for you in that case.

How long does Wegovy stay in your system?

Wegovy stays in your body for 5-7 weeks after your last dose. This medication is a long-acting medication, which is why you only need to take 1 dose a week for it to be effective. Because of this, it takes a longer period of time for it to be fully removed from your body. You may find during this time that your appetite is lower than usual, but it should return to normal 5-7 weeks after your last dose of Wegovy.

Wegovy is a highly effective weight loss medication, and you could lose up to 15% of your starting weight over the course of this medication. It also works for most people that use it, as studies have shown that more than 80% of those that take Wegovy can expect to see positive weight loss results beyond what they would have had with just dieting or exercise.

How much weight can I lose on Wegovy?

Clinical trials that tested the weight loss results of Wegovy showed that:

• 83% of adults taking Wegovy lost 5% or more weight, compared to 31% taking a placebo
• 66% of adults taking Wegovy lost 10% or more weight, compared to 12% taking a placebo
• 48% of adults taking Wegovy lost 15% or more weight, compared to 5% taking a placebo
• 30% of people taking Wegovy lost 20% or more weight, compared to 2% of people taking a placebo
• On average, people lost between 14% and 17% of their starting weight. This means that if you had a starting weight of 100 kg, you’d lose 14kg to 17kg.

These results found that people taking Wegovy lost significantly more weight than those who didn’t and attempted to lose weight through exercise and diet alone.

Wegovy comes in the form of an injectable pen, which you’ll inject yourself with once a week. It’s recommended to take it at the same time and day every week to get the best effect from Wegovy. You don’t need to measure your dose, as each pen contains 4 doses that will last for 4 weeks. You can inject Wegovy into your lower abdomen, thigh, or upper arm (with the help of someone else), depending on which is easiest and most comfortable for you.

Step by step guide to taking Wegovy

• Wash your hands and the injection site with warm soapy water to prevent contaminating the needle.
• Remove the pen cap and look through the small viewing window, where you can see the Wegovy liquid in the pen. Make sure that the liquid is clear and colourless. If it is not, do not use this pen.
• Push a new needle onto the pen and remove the caps. You should always use a fresh needle with every dose to prevent contamination or infection. Never reuse a needle or use a needle that’s unsealed, bent, or broken.
• If it’s your first time using this pen, you’ll need to check the flow. You can do this by turning the “dose selector” on the end of the pen until you reach the ‘flow check’ symbol (2 dots and a line). When you press the button, a small droplet of Wegovy should form on the tip of the needle. If it does not, you may need to replace the needle or use a new pen.
• You are now ready to set your dose. Turn the dose selector until you reach your prescribed dose.
• Insert the needle into your skin and press the button, holding it down until the number on the dose counter reaches 0. Continue holding the button down after it reaches 0, and then count to 6. This makes sure all of the medication is properly injected.
• Remove the needle slowly from your skin, and then dispose of the needle and cap in the provided sharps bin.

Where is the best place to inject Wegovy?

The best place to inject Wegovy is your upper arm, your upper leg, or your stomach. These spots are chosen because they are easily accessible for an injection, and can be less painful than other areas as they have higher amounts of body fat. It’s recommended that you get help if you want to inject Wegovy into your upper arm, as it’s more difficult to see and reach on your own.

Do I need to change where I inject each time?

Yes, even if you want to use the same part of your body every time you take Wegovy, you should still choose a different area of skin. Some people find it more comfortable to change which body part they inject into every week, as this can reduce any soreness or irritation.

What if I miss a dose?

If you miss your dose of Wegovy, what you should do depends on how long it is until your next dose. If your next dose of Wegovy is more than 3 days away, then you should take a dose of Wegovy as soon as possible and then take your next dose as normal. If your next dose of Wegovy is less than 3 days away, then you shouldn’t take the missed dose as it could cause unintended side effects. Continue as normal with treatment after your missed dose.

If you keep missing doses of Wegovy, speak to your doctor as it may not be as effective. If it’s been longer than 2 weeks since your last dose, you will have to start the Wegovy dosage schedule again.

Can I split my dose?

No, you should not split your dose of Wegovy. Only take Wegovy exactly as prescribed by your doctor.

How long does a pen last?

Each Wegovy pen lasts for 4 weeks. It has enough medication for 4 doses inside each pen, and you take 1 dose every week.

There are 5 different doses of Wegovy: 0.25 mg, 0.5mg, 1 mg, 1.7 mg, and 2.4 mg. Each dose comes in its own colour pen. Each pen contains 4 doses and lasts for 4 weeks before you need to switch pens.

What is the recommended dosage of Wegovy?

Wegovy dosage starts low and increases gradually as you get used to the medication. This is done over a period of a few months.

Month 1: You will start with the recommended dose of 0.25mg.

Month 2: Your dose will be increased to 0.5mg.

Month 3: Your dose will be increased to 1mg.

Month 4: Your dose will be increased to 1.7mg.

Month 5 and beyond: Your dose will be increased to 2.4mg, which is the maintenance dose. This is the dose you will continue taking for the rest of your treatment.

To help make sure you’re always using the correct dose, your doctor will give you clear advice and instructions. Each dose of Wegovy also comes in a different colour, so you’ll quickly and easily be able to tell which dose you need and what it looks like.

You’ll always be given a clear dosing schedule by your doctor and they will be available to support you if you have any questions or need help.

Wegovy is for overweight or obese people with a BMI of over 30, or over 27 if you have a pre-existing medical condition that is affected by your weight or a risk factor, such as high blood pressure. In the UK, only adults who match these criteria and have a prescription from a doctor can take Wegovy.

You should not take Wegovy if:

• you’re pregnant, you plan to become pregnant, or you’re breastfeeding
• you have had a serious allergic reaction to any of the ingredients in Wegovy

In addition, you should tell your doctor if you:

• have had problems with your pancreas or kidneys
• have type 2 diabetes and a history of diabetic retinopathy

Some medications can interact with Wegovy, causing unpleasant side effects. Speak to your doctor if you are taking any of the following:

• antidiabetic drugs, for example sulfonylureas and insulin, which can increase the risk of low blood sugar
• other GLP-1 agonists such as Saxenda or Mounjaro can increase the risk of all side effects and should never be taken alongside each other

Less serious and more common side effects of Wegovy may include:

• nausea
• diarrhoea
• vomiting
• constipation
• lower stomach pain
• headache
• tiredness
• upset stomach
• dizziness
• feeling bloated
• belching and gas
• heartburn

Contact your doctor or healthcare professional if any of these side effects bother you or don’t go away. Most Wegovy side effects are strongest when you first start treatment or after a dose increase.

Wegovy may cause serious side effects including:

• inflammation of your pancreas (pancreatitis)
• gallbladder problems
• increased risk of low blood sugar (hypoglycemia) in patients with type 2 diabetes
• kidney problems, which are more likely if you’ve got diarrhoea or vomiting and become dehydrated
• serious allergic reactions
• change in vision in patients with type 2 diabetes
• increased heart rate
• gastroparesis

If you notice signs of any of these serious Wegovy side effects you should contact your doctor or a healthcare professional. In an emergency, such as a serious allergic reaction, call 999 or go to A&E straight away.

While Wegovy is a highly effective medication that works for most people, it’s not right for everybody. Fortunately, there are other weight loss medications that may be able to help you with your weight loss journey. Some reasons you may want to try another medication include:

• You don’t meet the criteria to take Wegovy
• Wegovy is not suitable for you due to a pre-existing condition
• Wegovy may interact with a medication you are taking
• You don’t want to take an injection

Weight loss injections

If you’re comfortable with taking an injection but find that Wegovy isn’t right for you, then there are other options.

Mounjaro

Mounjaro is a similar weight loss injection, and contains the active ingredient tirzepatide. Like Wegovy, it helps you lose weight by reducing your appetite. Combined with a healthy diet and exercise, this can lead to patients losing up to 22.5% of their starting weight (after 72 weeks of treatment on a maintenance dose of 15mg). Like Wegovy, Mounjaro is a weekly injection.

Saxenda

Saxenda is a weight loss injection that is similar to Wegovy. It contains the active ingredient liraglutide, which is in the same family of medications of Wegovy (semaglutide). It helps you lose weight by suppressing your appetite, reducing the amount of food you need to eat to feel full. While Wegovy is a weekly injection, you need to inject Saxenda every day. Saxenda is currently long-term out of stock, although you can still get Wegovy and Mounjaro.

Weight loss tablets

If you're not comfortable taking an injectable medicine, then weight loss tablets may be a better option for you. Weight loss tablets work differently to injections.

Orlistat (Xenical)

Orlistat and Xenical are weight loss tablets that change how your body absorbs fat, reducing the amount of dietary fat absorbed by your body when you eat food. This excess fat is instead passed through the body when you go to the bathroom. You can take them up to 3 times a day, with meals containing fat. Orlistat is the unbranded (generic) version of Xenical.

Alli

Alli is a lower dose version of orlistat that is available over the counter, which means you don’t need a doctor’s prescription to get it. It works in the same way as orlistat, by reducing the amount of fat absorbed from food you eat. A pharmacist will still need to check your suitability before you can buy it.

Mysimba

Mysimba is a weight loss tablet that also works on areas of your brain responsible for appetite helping you lose weight by suppressing your hunger levels. This may be a good alternative for people who want a medication that works like Wegovy, but don’t want to take an injection.

Is Wegovy safe?

Yes, Wegovy is safe for most people to take if a doctor has said it’s suitable for them. However, there are certain conditions and health circumstances that may make your doctor less likely to prescribe the medication. For example, if you have or have had pancreatitis, your doctor might not prescribe Wegovy.

Can I use Wegovy if I am pregnant or breastfeeding?

No, it’s not safe to use if you’re pregnant or plan to become pregnant, and you should stop using it 2 months before you plan to become pregnant. It’s not known if Wegovy passes into your breast milk, so it’s recommended to avoid it if you are breastfeeding or plan to breastfeed.

Can I drink alcohol while taking Wegovy?

You can drink alcohol while taking Wegovy. There are no known interactions between Wegovy and alcohol. However, alcohol and Wegovy both lower blood sugar levels, so it is advisable that you monitor your reaction to the medication in case you become lightheaded or dizzy. It can also make other side effects more likely, such as nausea or vomiting, so it’s best to avoid alcohol after you first start taking Wegovy or after a dose increase.

Can I drive while taking Wegovy?

Yes, you can drive while taking Wegovy, but it is recommended that you proceed with caution until you are sure how Wegovy affects you. If you get dizzy or lightheaded, it’s best to avoid driving until you feel better.

Can I take Wegovy long-term?

Yes, Wegovy has been approved by the The Medicines and Healthcare products Regulatory Agency (MHRA) for long-term treatment of obesity, and can be used for as long as it remains beneficial.

Is Wegovy addictive?

There is no evidence to suggest Wegovy is addictive.

Does Wegovy affect birth control?

Because Wegovy slows down how quickly your stomach empties, some people believe that this may reduce the effectiveness of the pill as the hormones may not be fully absorbed. However, it is currently not proven whether or not Wegovy reduces the effectiveness of birth control, as no clinical studies have been conducted to test this.

Why am I not losing weight on Wegovy?

If you’re not losing weight while taking Wegovy, make sure that you’re following a healthy diet plan and are exercising. Wegovy is most effective when taken alongside other weight loss strategies. Snacking between meals or eating unhealthy foods can limit the effectiveness of Wegovy.

Make sure you are taking the right dose at the right time, and ensure that you do not miss any doses. Wegovy may also just not be right for you. Some people have genetic or medical conditions that cause Wegovy to not be as effective for them. While it is effective for most people, it doesn’t work for everybody. If you have been following a diet and exercise plan, and have been taking Wegovy correctly, then you should speak to a doctor about trying other weight loss medications that may be a better choice for you.