Mounjaro interactions: drugs to avoid when taking tirzepatide

Simon Edward • 24 February 2025

Are there any Mounjaro drug interactions to be aware of? Learn about the key medications to avoid.

If you're interested in using Mounjaro for weight loss, you might be wondering whether it's safe to take your usual medications at the same time.

There are a few Mounjaro drug interactions to be aware of. A drug interaction is when one drug interferes with the way another drug works.

If you're taking Mounjaro, using drugs that interact with it is not recommended and can be dangerous.

However, you should have a consultation with a doctor before you start treatment. In the consultation, your doctor will ask about the drugs you're taking so they can ensure it's safe for you to take Mounjaro alongside them.

But you can never have too much peace of mind. That's why we created this guide to Mounjaro drug interactions. We want you to have total confidence in the treatment you receive.

Please note, however, that this list may not be complete. Always check with your doctor before starting any course of treatment.

Insulin

You can take Mounjaro alongside insulin. However, special care is required. Your doctor may adjust your insulin dosage to make sure it's safe to take both treatments.

This is because both medications affect blood sugar levels in the body. Taking Mounjaro and insulin together increases the risk of hypoglycemia (low blood sugar).

It's particularly important to monitor your blood sugar levels while taking this combination of drugs. Look out for symptoms of low blood sugar, too, such as shakiness, sweating and an elevated heart rate. Tell your doctor or get medical help right away if you experience any of these symptoms.

Glinides

Glinides, like insulin, are a type of diabetes medication. Drugs in this category include repaglinide (Prandin), nateglinide (Starlix) and mitiglinide (Glufast).

The risk is the same here, too. Taking Mounjaro and glinides raises the risk of hypoglycemia, so your dosages must be carefully managed. Make sure to monitor your blood sugar levels and seek medical attention immediately if you experience symptoms of hypoglycemia.

Sulphonylureas

This is yet another class of diabetes medications that can cause hypoglycemia if taken alongside Mounjaro. Again, caution and careful monitoring is needed.

Examples of sulphonylureas include gliclazide and glipizide.

DPP4 inhibitors

DPP4 inhibitors work by preventing the breakdown of GLP-1 – the same hormone Mounjaro mimics to help with weight loss.

For this reason, it's not recommended to take DPP4 inhibitors at the same time as Mounjaro. If you're currently taking a DPP4 inhibitor and want to start taking Mounjaro, ask your doctor to move you to a safe alternative like metformin.

Other GLP-1 weight loss injections

Mounjaro is part of a class of medications called 'GLP-1 receptor agonists' or 'incretin mimetics'. Examples include semaglutide (Wegovy) and liraglutide (Saxenda).

You should not take two kinds of incretin mimetics at the same time. Doing so could be very dangerous. You would increase the risk and severity of side effects, including serious side effects, and might lose weight too quickly.

The oral contraceptive pill

Mounjaro is known to make the oral contraceptive pill work less effectively. Taking them together increases the chance of an unwanted pregnancy. And if you're taking the contraceptive pill to manage period pain or the symptoms of another health condition, it may make these symptoms worse.

If you're taking the contraceptive pill and you want to begin treatment with Mounjaro, it's recommended to choose an alternative form of contraception.

SemaPen is a trusted weight loss clinic. As part of Phoenix Health, we can offer a range of proven obesity treatments. That includes dietary advice, bariatric surgery and the weight loss medications Wegovy and Mounjaro.