The most common side effects with Wegovy (which may affect more than 1 in 10 people) are headache, nausea (feeling sick), vomiting, diarrhea, constipation, and abdominal (belly) pain.
Potential side effects are generally mild and tend to diminish as the body adjusts to the medication:
Up to 44% of patients experience nausea, vomiting, diarrhea, constipation and abdominal pain. Less commonly reported side effects are headache, fatigue, dizziness, indigestion. Hair loss occurs in some patients. In some instances patients are unable to tolerate the medication.
There are however some potential serious side effects you need to be aware of (if you have any concerns or questions regarding these, it is essential that you contact the Everwell Medical Team before you start your treatment):
Pancreatitis (inflammation of the pancreas): Symptoms include severe abdominal pain, nausea, and vomiting. Incidence is low but significant. This can be life threatening.
Gallbladder Issues: Such as gallstones, potentially leading to cholecystitis. Symptoms include severe abdominal pain, nausea, and yellowing of the skin or eyes.
Thyroid Tumours: Animal studies indicated a risk of medullary thyroid carcinoma (MTC), although this hasn’t been observed in humans. Monitor for neck lumps or difficulty swallowing. Any change to your voice.
Hypoglycemia: Especially when combined with diabetes medications called sulphonylureas or insulin, occurring in ~6% of users with diabetes.
Kidney Injury: Due to dehydration from severe vomiting or diarrhea.
Diabetic Retinopathy Complications: Worsened vision in patients with pre-existing conditions.
Allergic Reactions: Rare but potentially life-threatening, including symptoms like swelling of the face or throat, difficulty breathing, or severe rash.
Tachycardia (Increased Heart Rate): Rare but possible, with heart rate increases of 1–4 beats per minute observed.
Incidence of Serious Side Effects
In clinical trials, approximately 9.8% of patients reported serious side effects compared to 6.4% on placebo.
Many of these resolved without requiring discontinuation of the drug, but regular monitoring is essential.
For the full list of side effects and restrictions of Wegovy, see the Patient Information Leaflet provided with the medication.