What serious side effects should you watch for with Mounjaro?
Mounjaro (tirzepatide) can cause rare but serious side effects that require prompt medical attention. One of the most important to watch for is acute pancreatitis, which presents as sudden, severe stomach pain that may spread to the back and does not go away. If this occurs, you should stop taking the medicine and seek urgent help immediately. Gallbladder problems are another risk, with warning signs such as persistent upper abdominal pain (often on the right side), fever, yellowing of the skin or eyes (jaundice), or pale stools. These symptoms need prompt medical assessment.
Severe or ongoing vomiting and diarrhoea can lead to dehydration, which in turn can cause kidney complications. It’s important to maintain fluid intake, and medical help should be sought if you are unable to keep liquids down. If Mounjaro is used with insulin or sulfonylureas, there is a higher risk of hypoglycaemia (low blood sugar). Symptoms include shakiness, sweating, dizziness, fast heartbeat, or confusion—severe cases may require emergency treatment. Finally, serious allergic reactions are possible, including swelling of the face or tongue, breathing difficulties, or severe rash, which require immediate emergency care.
- Acute pancreatitis: sudden, severe abdominal pain radiating to the back—stop the medicine and seek urgent care.
- Gallbladder issues: upper abdominal pain, fever, jaundice, or pale stools—contact a doctor promptly.
- Dehydration and kidney problems: persistent vomiting or diarrhoea can be dangerous if fluids cannot be kept down.
- Low blood sugar (with insulin or sulfonylureas): shakiness, sweating, confusion, or fainting—treat quickly and seek emergency help if severe.
- Serious allergic reactions: swelling, breathing difficulties, or rash—call emergency services immediately.
Any suspected side effects can be reported via the UK Yellow Card scheme, and patients should always inform their healthcare team promptly about concerning symptoms.