Website last updated 29/06/2025
Weight Loss Injections (Wegovy and Mounjaro)
- Mental Health. Mounjaro and Wegovy can cause changes in mood.
- Delayed Gastric Emptying. Monitor patients on oral narrow therapeutic index drugs.
- Risk of acute pancreatitis. Signs include sudden severe abdominal pain, nasuea and/or vomiting and fever. Refer patient to A&E if these symptoms develop.
- Contraception. Potential risk of reduced efficacy with oral contraception. Switch to non-oral contraception or use barrier method.
- Licensed for use in patients with a BMI of at least:
30kg/m²
27kg/m² with weight related co-morbidities (such as hypertension, pre-diabetes etc)
27.5kg/m² and a BAME background
- It may take up to 8-12 weeks before patient's have noticeable weight loss
- Licensed for use up to 2 years
- Patients can switch between Wegovy and Mounjaro, however should be started on the lowest dose of the new medication
- No wash- out period is needed when switching between these two medications
- Patient's should be advised on the symptoms of acute pancreatitis:
-
suddenly getting severe pain in the centre of your tummy (abdomen)
-
feeling or being sick
-
a high temperature of 38C or more
- Advise patients to go to A&E or call 111 if these symptoms develop
- Advise patients to stop using Mounjaro/Wegovy and call 111 or book an appointment with their GP if they notice negative changes in their mental health
- Mild side effects can be managed with OTC medication, such as cyclizine for nausea, loperamide for diarrhoea.
What dose should the patient be on?
It is recommended that patients increase their dose every 4 weeks until they reach a dose where they have sufficient appetite suppression with minimal or no side effects
Do you have to titrate down to stop Mounjaro/Wegovy?
No, patients can simply stop injecting at any time, regardless of the dose they are on
How long should the patient stay on Wegovy/Mounjaro?
They should continue until they reach a healthy BMI for their ethnicity
How much risk does acute pancreatitis carry?
80–85% of people with acute pancreatitis will have mild self-limiting disease, with a mortality rate of 1–3%