Side Effects of Wegovy & How to Manage Them

Side effects are a normal part of starting many medications, including Wegovy, and it is normal to feel concerned about what to expect. The good news is that most people only experience mild and temporary Wegovy side effects, which tend to improve as your body gets used to the treatment.

This guide is here to help you feel informed and reassured. We’ll explain the most common side effects, how to manage them at home, and when it’s important to speak to a doctor. While serious side effects are possible, they are less common, and it can help to understand what to look out for, so that you can use Wegovy safely and confidently.

Wegovy has some common side effects that usually happen within the first month of treatment. These are often mild and will go away as your body adjusts to the medication.

Very common side effects (affecting more than 1 in 10 people) include:

• diarrhoea
• headaches
• constipation
• stomach pain
• weakness or tiredness
• nausea and vomiting (feeling or being sick)

Common side effects (affecting up to 1 in 10 people) include:

• gallstones
• hair loss
• bloating
• upset stomach or indigestion
• dizziness
• burping or gas (flatulence)
• heartburn or acid reflux
• skin reactions at the injection site, such as itching, redness, soreness, and swelling
• hypoglycemia (low blood sugar), usually in patients who have diabetes
• an inflamed stomach (gastritis)
• taste changes
• changes in skin sensation (more frequent with the 7.2mg dose)

You can treat most of these side effects at home with over-the-counter medication, like paracetamol for headaches. You should also make sure you’re hydrated if you’re getting side effects like diarrhoea or vomiting.

The frequency of the most common Wegovy side effects during the STEP-1 trial is shown in the following table.

Wegovy also has some less common side effects, which can affect up to 1 in 100 people who take it.

Uncommon side effects may affect up to (1 in 100 people) include:

• low blood pressure
• feeling dizzy or lightheaded on standing or sitting up because of a drop in blood pressure
• an increase in pancreatic enzymes, which can be seen in blood test results
• a fast heartbeat
• delayed stomach emptying
• low blood sugar in people without diabetes
• yellowing of the skin and/or eyes, indicating increased bilirubin levels in the blood

Many of the side effects of Wegovy last a few days to a few weeks. Side effects are often mild and should not bother you too much. While you increase your dosage, you may find some side effects, such as dizziness, headaches, and nausea will get worse, although as your body adjusts to the dosage they should gradually get better.

You may find that side effects can affect you at different times throughout the day, such as just after eating or after taking your dose.

In rarer cases, side effects can last 2 weeks or more, although they should start to get better as time goes on.

Will side effects go away if I stop taking Wegovy?

If you stop taking Wegovy, your side effects should go away within a few weeks. This depends on how long you have been taking Wegovy, as your body will need to readjust.

If your side effects are severe or impacting your day-to-day life, speak to your doctor.

Many of Wegovy’s side effects are not long-term and will stop on their own, or once you stop using the medication. However, there are some less common side effects that may develop during longer-term use. These are rare and include pancreatitis or swelling of the gallbladder, but it is important to be aware of them.

Some of the longer-term side effects linked to Wegovy usually develop within weeks or months of starting treatment and include:

• pancreatitis – a rare but serious condition that causes symptoms that come on suddenly or do not go away, such as severe, persistent abdominal pain, which may spread to your back, nausea, and vomiting
• gallbladder issues – rapid weight loss increases the chance of gallstones and gall bladder inflammation, which can cause upper right-sided abdominal pain, fever, nausea, vomiting, and yellowing of the skin or eyes (jaundice)
• kidney problems – dehydration caused by ongoing vomiting and diarrhoea can affect kidney function, signs include reduced urination, swelling of the legs and ankles, or feeling very tired

Speak to your doctor straight away if you think you have any of these side effects.

Nutritional considerations during long-term Wegovy use

Because Wegovy is a long-term weight loss medication and works by suppressing your appetite, you might find that you are eating a lot less than you may be used to. Although this can support weight loss, it can also make it harder to meet your nutritional needs, especially if you are not following a healthy, balanced diet.

Some potential issues include:

• reduced intake of vitamins and minerals, like iron, calcium, vitamin B12, and vitamin D
• inadequate protein intake, which can affect your muscle mass, energy levels, and general health
• low fibre intake, which can make digestive side effects, like constipation worse

There are things you can do to minimise the chance of nutrient deficiencies while taking Wegovy. These include:

• focusing on nutrient-dense foods, including lean proteins, wholegrains, fruits, vegetables, and healthy fats
• prioritising protein intake, even if your appetite is low, by including protein at every meal
• staying hydrated throughout the day to prevent dehydration
• speaking to your doctor about supplements, particularly if you follow a specific diet, such as plant-based or vegan

Side effects may get worse briefly when you increase your dose, especially on the higher maintenance doses of 1.7, 2.4, and 7.2mg. The highest 7.2mg dose is also associated with a higher rate of skin sensations, such as burning, stabbing, or tingling, also known as dysaesthesia. The STEP UP trial reported 22.9% of people on the 7.2mg dose experienced this side effect compared to 6% on the 2.4mg dose.

Your dose is increased slowly to reduce this effect and give your body more time to get used to the medication. If your side effects worsen to a point where they’re unmanageable, speak to your doctor.

It is most common to get Wegovy side effects at the start of your treatment or after a dose increase, but there are things you can do to minimise the chance of getting them or manage them at home.

➤ There are a number of over-the-counter options that could help ease side effects, however you should speak to a doctor about your side effects if they are not going away and are interfering with your daily life.

Wegovy can cause some serious side effects that require medical attention. If you notice any of the following symptoms, you should seek medical advice straight away by calling 111, or 999 if it’s an emergency.

Serious side effects of Wegovy include:

• anaphylaxis (a severe allergic reaction), which can make it harder to breathe, cause sudden facial swelling (angioedema), and an increased heart rate
• complications of diabetic retinopathy (diabetic eye disease), if you have this condition and notice changes in your vision, speak to your doctor straight away
• acute pancreatitis (an inflamed pancreas), which can cause intense and long-lasting pain in your stomach or back
• non-arteritic anterior ischaemic optic neuropathy (NAION), a very rare side effect of Wegovy that can cause loss of sight – if you develop any changes or issues with your sight, speak to your GP or call 111 before continuing treatment

If you get any serious side effects whilst taking Wegovy, you should stop treatment and speak to your doctor after seeking appropriate medical treatment.

Yes, Wegovy is safe if prescribed to you by a doctor. Although Wegovy may have some serious side effects, they are no different to any other medication.

In a clinical trial from 2021, patients who received 3mg of semaglutide once a week mainly reported mild to moderate side effects such as nausea and vomiting. These side effects went away over time.

Will drinking alcohol make my side effects worse?

Drinking alcohol can make side effects worse, especially if you get low blood sugar, nausea, or headaches. Alcohol irritates the stomach lining, so when combined with Wegovy’s ability to slow gastric emptying, it can cause more frequent vomiting, dizziness, and intense hangovers.

Although there is no direct link between Wegovy and alcohol, both alcohol and Wegovy lower blood sugar levels, which can cause dizziness, fainting, and make you feel generally unwell. This is also particularly dangerous for people with diabetes.

When taking Wegovy for weight loss, you should follow a calorie-controlled diet to maintain a calorie deficit, a key factor in weight loss. However, alcohol is also often full of empty calories, that is, calories that have no nutritional benefit. So, when you drink alcohol, you may be unintentionally taking on calories, which may slow your progress down.

The bottom line is, you can drink alcohol whilst taking Wegovy, but it is best consumed in moderation to minimise the chance of intense side effects and slow weight loss.

You should speak to a doctor about your side effects if they are not going away and are interfering with your daily life. Some side effects are serious and need urgent medical attention. If you get any of the following Wegovy side effects, you should speak to your doctor or call 111 or 999 in an emergency:

• severe abdominal pain that may feel intense and radiate to your back, and can be a sign of acute pancreatitis
• allergic reaction, which may include symptoms such as swelling of the face, lips, tongue, or throat, difficulty breathing and/or swallowing, and a severe rash
• vision changes, including blurred or partial loss of vision, which could be a sign of diabetic eye disease or non-arteritic anterior ischaemic optic neuropathy (NAION)
• lower back or stomach pain, difficulty going for a pee, or a change in the colour of your pee could suggest kidney or bladder stones
• severe constipation with stomach ache, bloating, or being sick, which could be a sign of a bowel obstruction

Wegovy is not an addictive medication so you shouldn’t get withdrawal symptoms. It is therefore safe to stop Wegovy whenever you need to without reducing your dose beforehand.

Yes, Wegovy can interact with other medications, which is why you must tell your doctor about any prescribed, over-the-counter, or herbal medications you are taking before starting Wegovy, so that they can make sure it is safe for you.

If you take any medications that contain warfarin or any other medications that reduce blood clotting, let the doctor, nurse, or pharmacist prescribing Wegovy to you know.

Will side effects prevent me from driving?

Wegovy is unlikely to prevent you from driving, but it can sometimes cause dizziness or tiredness. You should be careful driving if you feel dizzy or overly tired, and speak to your doctor if your side effects are making it difficult to drive.

Can Wegovy cause flu-like symptoms?

Wegovy is not likely to cause flu-like symptoms and this is not currently a listed side effect. Wegovy may make you feel generally unwell as it can cause headaches and weakness, but these will get better as you get used to the medication.

Will Wegovy make me tired?

Wegovy can make you feel tired, but this side effect often goes away on its own within a few weeks.

Can Wegovy cause depression?

There are no listed side effects for mood changes or depression whilst taking Wegovy, and the MHRA have not found conclusive evidence that GLP-1 medications, including Wegovy, can cause depression or suicidal thoughts. One study reported that adverse psychiatric events accounted for 1.2% of reports linked to semaglutide, tirzepatide, and liraglutide.

However, there have been anecdotal reports that Wegovy can cause mood changes and depression. Some side effects may also indirectly affect mood. If you get any mood changes or thoughts of self-harm while taking Wegovy, contact your doctor immediately.

Does Wegovy cause hair loss?

A common side effect of Wegovy is temporary and mild hair loss, with around 3% of patients reporting it. It is not a direct effect of the medication but rather a result of telogen effluvium, a common and temporary form of sudden hair loss caused by stress, illness, or physiological changes in the body. In this instance, the rapid weight loss caused by Wegovy can result in hair loss, but this usually improves once your weight stabilises.

Can Wegovy cause acid reflux?

Yes, Wegovy can sometimes cause reflux symptoms, but these can be treated with over-the-counter medications. You can also speak to your doctor who can prescribe an acid reflux treatment.

To limit acid reflux symptoms, avoid spicy and high-fat foods, avoid eating just before bed, and eat smaller, more frequent meals.

Can Wegovy cause cancer?

There is no clear evidence that Wegovy causes cancer. In the US, there are boxed warnings for thyroid cancer, mostly based on rodent studies and not humans, and multiple endocrine neoplasia (MEN-2), but these are not contraindications in the UK because the UK and US have different approaches to licensing medications. If you are concerned about cancer and Wegovy, speak to your doctor.