Like all medicines, Wegovy^® pill can cause side effects, although not everybody gets them.

Serious side effects 

Common: may affect up to 1 in 10 people

• Complications of diabetic eye disease (diabetic retinopathy). If you have diabetes you should inform your doctor if you experience eye problems, such as changes in vision, during treatment with this medicine

Uncommon: may affect up to 1 in 100 people 

• Inflamed pancreas (acute pancreatitis) which could cause severe pain in the stomach and back which does not go away. This is a serious, potentially life-threatening condition. You should see a doctor immediately if you experience such symptoms.
  Stop using this medicine and seek urgent medical help if you experience: Severe, persistent pain in the stomach area (abdomen), with or without nausea and vomiting. This could be a sign of acute pancreatitis, which is serious and potentially life-threatening
• Kidney or bladder stones. Signs may include back or lower abdomen pain, difficulty in urination or change in colour of your urine

Rare: may affect up to 1 in 1,000 people

• Severe allergic reactions (anaphylactic reactions, angioedema). You should seek immediate medical help and inform your doctor straight away if you get symptoms such as breathing problems, swelling of face, lips, tongue, and/or throat with difficulty swallowing, wheezing, fast heartbeat, pale and cold skin, feeling dizzy or weak
• Hip fractures

Very rare: may affect up to 1 in 10,000 people

• A medical condition of the eye called non-arteritic anterior ischaemic optic neuropathy (NAION), which may cause loss of vision to one of your eyes without any pain. You should urgently contact your doctor if you notice sudden or gradually worsening eyesight (see section 2 of your Patient Information Leaflet (PIL): “Sudden changes to your eyesight”) 

Not known: frequency cannot be estimated from the available data

• Bowel obstruction. A severe form of constipation with additional symptoms such as stomach ache, bloating, vomiting etc.

Other side effects

Very common side effects: may affect more than 1 in 10 people

• Headache
• Feeling sick (nausea)
• Being sick (vomiting)
• Diarrhoea
• Constipation
• Stomach pain
• Feeling weak or tired
• Upset stomach or indigestion

These usually go away over time. 

Common side effects: may affect up to 1 in 10 people

• Feeling dizzy
• Burping
• Gas (flatulence)
• Bloating of the stomach
• Inflamed stomach (‘gastritis’) — the signs include stomach ache, feeling sick (nausea) or being sick (vomiting)
• Reflux or heartburn — also called ‘gastro-oesophageal reflux disease’
• Gallstones
• Hair loss
• Change in the way food or drink tastes
• Change in skin sensation
• Low blood sugar (hypoglycaemia) in patients with diabetes

The warning signs of low blood sugar may come on suddenly. They can include: cold sweat, cool pale skin, headache, fast heartbeat, feeling sick (nausea) or very hungry, changes in vision, feeling sleepy or weak, feeling nervous, anxious or confused, difficulty concentrating or shaking.

Your doctor will tell you how to treat low blood sugar and what to do if you notice these warning signs.

Low blood sugar is more likely to happen if you also take a sulfonylurea or insulin. Your doctor may reduce your dose of these medicines before you start using this medicine.

For a full list of side effects, warnings and precautions, please refer to the Patient Information Leaflet (PIL).