Can I take Mounjaro and Insulin together?

Why this happens

Both Mounjaro and insulin work to lower your blood sugar levels. When used at the same time, their effects are additive, meaning they work together to lower blood sugar much more powerfully than either drug would on its own.

Additionally, Mounjaro slows down how quickly your stomach empties, which can change how fast your body absorbs sugar from food, potentially making it harder to time your insulin doses correctly.

What you should do

You must speak to your doctor before starting Mounjaro if you are already using insulin. Your doctor will likely need to reduce your insulin dose to prevent your blood sugar from dropping too low.

You should monitor your blood sugar levels more frequently when starting Mounjaro or changing your dose. Always carry a fast-acting glucose source (like glucose tablets or a sugary drink) to treat a hypo if it occurs.

Important precautions

Hypoglycaemia (Low Blood Sugar)

Using Mounjaro alongside insulin significantly increases your risk of severe hypos. You must monitor your blood sugar more frequently, and your doctor may need to reduce your insulin dose before you start Mounjaro.

Severe gastrointestinal disease

Mounjaro can cause severe dehydration due to vomiting and diarrhoea. If you have pre-existing stomach or bowel problems, such as gastroparesis, this medicine may worsen your condition. Ensure you maintain a high fluid intake to prevent kidney damage.

Pancreatitis

Stop using Mounjaro and seek immediate medical help if you experience severe, persistent stomach pain (which may radiate to your back), as this can be a sign of acute pancreatitis.

Food and drink warnings

Alcohol

It is best to avoid or strictly limit alcohol when taking these medicines. Alcohol can cause your blood sugar levels to drop dangerously low (hypoglycaemia). It can also mask the warning signs of a 'hypo', making it harder for you to treat. For Mounjaro specifically, alcohol may also worsen stomach-related side effects like nausea and vomiting.

Large or high-fat meals

Mounjaro slows down how quickly your stomach empties. Eating very large or high-fat meals can lead to significant discomfort, bloating, and nausea because the food stays in the stomach longer. It is often recommended to eat smaller, more frequent meals.

Caffeine (Coffee, Tea, Energy Drinks)

Caffeine can affect how your body uses insulin and may cause blood sugar levels to rise or fall unpredictably. Monitor your blood sugar levels closely if you change your caffeine intake.

Using other medicines

Taking multiple medicines? Our Medicines Interaction Checker helps you check whether your prescriptions, over-the-counter medicines, and supplements are safe to take together. Simply search for your medicines to see potential interactions and what to do about them.

Disclaimer

This information is for general educational purposes only and should not be relied upon as a substitute for professional medical advice. Always consult your GP, pharmacist, or another qualified healthcare professional before making decisions about your medications. Individual circumstances may vary, and only a healthcare professional who knows your medical history can provide personalised guidance.