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 general information and is not a substitute for a consultation. These are prescription medicines; start, change or stop them only with your doctor.