Wegovy side effects: what’s normal and how to manage them

As the popularity of Wegovy continues to grow, so do questions about its side effects. While many people achieve successful weight loss with Wegovy, it’s common to experience some temporary symptoms as your body adjusts to the treatment, particularly during the first few weeks or after increasing your dose.

The good news is that most side effects are temporary, manageable at home and tend to improve as your body adjusts to the medication. Knowing what’s considered normal and when to seek medical advice can help you feel more prepared and confident during your treatment journey.

What is Wegovy and why does it cause side effects?

Wegovy contains semaglutide, a medication that works by mimicking a natural gut hormone called GLP-1. This hormone helps regulate appetite, slows down stomach emptying, and helps you feel fuller for longer.

As Wegovy changes the way your digestive system works, most side effects affect the stomach and gut. Symptoms are often more noticeable when starting treatment or after increasing to a higher dose.

Common Wegovy side effects

The most commonly reported Wegovy side effects include:

• Feeling sick (Nausea)

• Being sick (Vomiting)

• Diarrhoea

• Constipation

• Stomach pain

• Bloating

• Heartburn or indigestion

• Upset stomach

• Headache

• Tiredness

• Fatigue

• Dizziness

• Burping or excess gas

• Injection site reactions

Some people may also notice hair thinning during significant weight loss, although this is often linked to rapid weight loss itself rather than the medication directly.

Always read the patient information leaflet for a full list of potential side effects before starting any new medication.

Why do these side effects happen?

Most Wegovy side effects occur because the medication slows down digestion. Food stays in the stomach for longer, which helps reduce hunger but it can also lead to symptoms like nausea, bloating, constipation and reflux.

Changes in appetite and reduced calorie intake can also contribute to tiredness, headaches, or dehydration, especially if you’re not eating or drinking enough.

How to manage Wegovy side effects

Nausea

Nausea is one of the most common side effects when starting Wegovy.

You may find it helps to:

• Eat smaller meals more frequently

• Avoid fried, greasy or spicy foods

• Eat slowly and stop when you feel full

• Drink water regularly throughout the day

• Ensure your diet is low in carbohydrates

• Get fresh air

• Ear or drink foods containing ginger

Constipation

As digestion slows down, constipation can occur during treatment.

To help:

• Increase fibre through foods like oats, fruit, vegetables, and wholegrains

• Drink plenty of water and other fluids and avoid alcohol

• Stay active with regular walking or exercise

• Ensure you are only eating to the fullness point and not beyond this. Even if this means you stop eating halfway through a meal

If constipation becomes uncomfortable, a pharmacist may recommend a suitable laxative.

Diarrhoea

Diarrhoea is usually temporary but can increase the risk of dehydration.

Helpful tips include:

• Drinking plenty of fluids such as water or squash

• Eating simple, bland meals like toast, rice, bananas or boiled potatoes

• Avoiding fatty or spicy foods

• Resting while symptoms settle

• Using oral rehydration solutions if needed

If diarrhoea lasts longer than a few days or becomes severe, speak to a healthcare professional.

Heartburn or indigestion

Some people notice reflux or a burning sensation in the chest.

This may improve if you:

• Avoid eating late at night or just before bed

• Reduce caffeine intake

• Limit spicy or high-fat foods

• Eat smaller portions

• Stay upright after meals

• Avoid smoking and alcohol.

Headaches and tiredness

Headaches and fatigue can happen if you’re eating significantly less or becoming dehydrated.

Try to:

• Drink enough fluids throughout the day ( aim for a minimum of 2 litres per day)

• Prioritise nutrient dense foods such as lean proteins e.g ( eggs, salmon and chicken )

• Eat regularly and eat enough

• Aim for consistent sleep and rest

Do side effects get worse when the dose increases?

Many people notice side effects temporarily return or become stronger after moving up to a higher dose. This is a common part of dose escalation with Wegovy.

In most cases, symptoms improve again after your body adjusts. If side effects feel difficult to manage or are affecting daily life, speak to your prescriber as you may need to reduce your dose or titrate slowly before increasing your next dose.

When should you seek medical help?

Most Wegovy side effects are mild and improve over time, but some symptoms should never be ignored. Seek urgent medical advice if you experience any of the following:

Acute pancreatitis (inflammation of the pancreas)

Although rare, Wegovy has been linked to pancreatitis, which requires urgent medical attention.

Symptoms can include:

• Severe stomach pain that does not go away

• Pain spreading to your sides or back

• Nausea and Vomiting

• Fever or feeling seriously unwell

Stop taking Wegovy and seek immediate medical attention if you notice these symptoms.

Gallbladder problems

Rapid weight loss can increase the risk of gallstones and gallbladder inflammation in some people.

Signs to look out for include:

• Severe pain in the upper part of your abdomen

• Pain spreading to the shoulder or back

• Fever

• Nausea or vomiting

• Yellowing of the skin or eyes

• Clay coloured stools

These symptoms should be assessed urgently.

Severe allergic reactions

Serious allergic reactions are rare but can happen.

Seek emergency medical attention if you experience:

• Swelling of the lips, tongue, face, or throat

• Difficulty breathing or swallowing

• Wheezing

• Severe rash or hives

• Feeling faint or dizzy

• Very rapid heartbeat

Vision changes

Some people with diabetes may experience worsening diabetic eye disease while taking Wegovy.

Speak to your doctor if you notice:

• Blurred vision

• Sudden vision changes

• Loss of vision

Who should not take Wegovy?

Wegovy is not suitable for everyone. You should speak to your healthcare provider before starting treatment if you:

• Are pregnant or trying to become pregnant

• Are breastfeeding or plan to breastfeed

• Have a personal or family history of medullary thyroid cancer

• Have multiple endocrine neoplasia syndrome type 2 (MEN2)

• Have a history of pancreatitis

• Have severe kidney or liver disease

• Have severe digestive conditions or gastroparesis

• Are allergic to semaglutide or any other ingredients in the injection

Your prescriber will also review any other medications or health conditions before treatment begins.

Managing side effects with confidence

Experiencing mild side effects with Wegovy can be worrying at first, but symptoms like nausea, constipation, or diarrhoea are very common and usually temporary. Small lifestyle changes, staying hydrated, and giving your body time to adjust can make a big difference.

However, you should never ignore severe or persistent symptoms. If something doesn’t feel right contact your GP, call NHS 111 or speak to one of our healthcare professionals at Quick Meds, where our clinical team will provide support, reassurance and guidance throughout your treatment journey.

With the right support and realistic expectations, many people find Wegovy side effects become much easier to manage over time.