Mounjaro interactions: drugs to avoid when taking tirzepatide

Ready to take the next step? See if you're eligible for expert-led weight loss support.

Check your eligibility

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



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).


Picture of Nateglinide.

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.


  • Average 15-21% weight loss*
  • Tailored programmes built by real experts
  • Targeted support to make success feel simpler
  • Unique app with weight loss tools and lessons

Your journey starts here

Start your personalised weight loss plan in minutes.

1

Start your online consultation

2

Get approved by our clinical team

3

Begin your programme

Get started
Wondering if weight loss can cause depression? The simple answer: it depends on how you do it.
by Simon Edward • 9 October 2026
Wondering if weight loss can cause depression? The simple answer: it depends on how you do it.
Obesity is a leading cause of obstructive sleep apnoea.
by Simon Edward • 5 October 2026
Obesity is a leading cause of obstructive sleep apnoea. Does that mean weight loss injections can help? Let's look at the evidence.
Wondering where you'll notice weight loss first? Discover the early signs of fat loss
by Simon Edward • 2 October 2026
Wondering where you'll notice weight loss first? Discover the early signs of fat loss and why it's worth celebrating achievements beyond the scale.
A recent trial tested Wegovy for weight loss in children aged 6 to 11.
by Simon Edward • 30 September 2026
A recent trial tested Wegovy for weight loss in children aged 6 to 11. Does that mean younger children will soon be able to access the drug?
Retatrutide is an experimental weight loss drug that's not approved for treatment anywhere.
by Simon Edward • 28 September 2026
Retatrutide is an experimental weight loss drug that's not approved for treatment anywhere. So, why are websites offering it for sale in 2026?
Explore the fastest medically supervised weight loss options, from GLP-1 injections
by Simon Edward • 11 September 2026
Explore the fastest medically supervised weight loss options, from GLP-1 injections to total diet replacement, and learn why speed isn't everything.
Non-surgical weight loss procedures may help you lose weight without conventional surgery.
by Simon Edward • 1 September 2026
Non-surgical weight loss procedures may help you lose weight without conventional surgery. Learn about your options and which might suit you.
A new GLP-1 drug called 'avexitide' is in development, but it works very differently from Wegovy.
by Simon Edward • 31 August 2026
A new GLP-1 drug called 'avexitide' is in development, but it works very differently from Wegovy and Mounjaro. Get the facts in our guide.
Learn how medically supervised total diet replacement (TDR) programmes work
by Simon Edward • 28 August 2026
Learn how medically supervised total diet replacement (TDR) programmes work, who they're suitable for and what the evidence says.
Learn who total diet replacement programmes are designed for, how they work
by Simon Edward • 24 August 2026
Learn who total diet replacement programmes are designed for, how they work and whether they could support your weight loss goals.
More posts