Wegovy Side Effects: Complete UK Guide (2026)

Wegovy Side Effects: What You Need to Know in 2026

Wegovy (semaglutide) is a prescription medication approved by the UK’s Medicines and Healthcare products Regulatory Agency (MHRA) for weight loss in adults with obesity or overweight conditions. It works by reducing appetite and helping you feel full sooner. While Wegovy can be effective for weight management, it may cause side effects. Understanding these is important to manage them safely.

Always consult your GP before starting or stopping Wegovy. Your doctor will monitor your health and help you manage any side effects.

Common Side Effects

Many people experience some side effects, especially in the first few weeks as their body adjusts to Wegovy. The most common include:

• Nausea: Feeling sick is the most reported side effect. It can range from mild to moderate.
• Vomiting: Some people may vomit, especially if nausea is severe.
• Diarrhoea: Loose or frequent bowel movements can occur.
• Constipation: Some users experience constipation instead of diarrhoea.

These symptoms often improve with time and usually do not require stopping the medication.

How Long Do Side Effects Last?

For most people, side effects start soon after beginning Wegovy. They are strongest during the first 4 to 6 weeks and then gradually subside as your body adjusts. Nausea and digestive symptoms often ease after 1 to 2 months.

Your doctor may start you on a low dose and increase it slowly over several weeks to reduce side effects. If side effects continue beyond 2 months or are severe, tell your GP.

Tips to Manage Nausea

Nausea can be unpleasant but there are practical steps to help reduce it:

• Eat small, frequent meals: Avoid large meals which can worsen nausea.
• Choose bland foods: Plain toast, crackers, rice, and bananas are easier on the stomach.
• Stay hydrated: Sip water regularly, but avoid carbonated drinks if they increase discomfort.
• Avoid strong smells: Cooking smells or perfumes may trigger nausea.
• Take Wegovy with water: Follow your doctor’s instructions on dosing and timing.
• Rest: Sometimes lying down and breathing slowly can help settle your stomach.

If nausea is severe or persistent, let your GP know. They may adjust your dosage or suggest medication to control nausea.

Wegovy Face (Facial Ageing from Rapid Weight Loss)

Rapid weight loss on Wegovy can sometimes cause changes to facial appearance, often referred to as “Wegovy face.” This involves:

• Loss of facial fat, making cheeks look sunken or hollow.
• Loose skin around the jawline and neck.
• Appearance of premature ageing in facial features.

This effect is due to quick fat loss and volume reduction under the skin. While it is not medically harmful, it might affect self-esteem.

Ways to reduce or manage this include:

• Gradual weight loss rather than very rapid loss.
• Facial exercises and moisturisers to improve skin elasticity.
• Consulting a dermatologist for professional advice if concerned.

Your GP or a specialist can help if you notice unexpected facial changes.

Less Common Side Effects

Some people may experience less common side effects, including:

• Headache
• Dizziness
• Fatigue or tiredness
• Indigestion or stomach pain
• Injection site reactions — redness, swelling, or itching where the shot is given

Usually, these are mild and improve with time. Report any new or unusual symptoms to your GP.

Serious Side Effects (Rare)

Though serious side effects with Wegovy are rare, some can be severe and require immediate medical attention:

• Pancreatitis: Severe stomach pain that does not go away, sometimes with vomiting.
• Allergic reactions: Rash, itching, swelling, severe dizziness, or trouble breathing.
• Gallbladder problems: Pain in the upper right abdomen, fever, or jaundice (yellowing of skin or eyes).
• Changes in vision: Blurred vision or eye pain.
• Thyroid tumours: Very rare cases reported in animal studies; your doctor will monitor symptoms.

If you experience any of these, stop taking Wegovy and seek urgent medical care via NHS 111 or your nearest emergency department.

When to Contact Your Doctor

Contact your GP or healthcare professional if you experience: