Common side effects
- Nausea, especially in the first weeks and after each dose increase
- Vomiting, diarrhoea or constipation
- Bloating, burping or heartburn
- Feeling full quickly and eating much less
Reducing them
- Increase the dose slowly, as prescribed; do not rush to a higher dose
- Eat smaller meals and stop when you feel full
- Avoid fried, very fatty and very spicy food
- Drink enough water, especially if you have diarrhoea or vomiting
Who should not take them
- Anyone with a personal or family history of medullary thyroid cancer or MEN2 syndrome
- Pregnant or breastfeeding women; stop before trying to conceive, as advised by your doctor (for semaglutide, at least two months before)
- People who have had pancreatitis need careful assessment first
Situations that need care
- Insulin or sulfonylureas: the risk of low sugars rises, so doses may need lowering
- Contraceptive pills: tirzepatide can make the pill less reliable; use an extra method for four weeks after starting and after each dose increase
- Surgery or endoscopy: tell the anaesthetist, as food can stay in the stomach longer
- Diabetic eye disease: a rapid fall in sugar can briefly worsen it, so keep up with eye checks
- Muscle: rapid weight loss can include muscle, so eat enough protein and keep up strength exercise
See a doctor urgently for
- Severe, constant tummy pain, possibly spreading to the back, with or without vomiting
- Persistent vomiting or being unable to keep fluids down
- Pain in the upper right of the abdomen, fever or yellowing of the eyes
- A lump or swelling in the neck, hoarseness or difficulty swallowing
Buy safely
Use only medicine prescribed by your doctor and dispensed by a licensed pharmacy. Avoid pens sold online without a prescription, as fake and incorrectly dosed products are a real risk.
This guide is for general educational purposes and does not replace individual medical advice, diagnosis or treatment. Consult your doctor for advice specific to your health. These are prescription medicines; start, change or stop them only with your doctor.