5 Mounjaro Drug Interactions to Know About: Insulin, Birth Control Pills, and More

Mounjaro (tirzepatide) is a convenient, once-a-week injectable medication for Type 2 diabetes. It works by signaling your pancreas to release insulin when you eat. It also slows down how fast your stomach empties and lowers the amount of glucose (sugar) made by your liver.

Mounjaro was the first medication FDA approved in a new class of medications called glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonists. But beyond this, Mounjaro has made headlines for its ability to promote significant weight loss. With all the buzz surrounding it, your endocrinologist (diabetes specialist) may have mentioned it as an option for you.

If you’re starting Mounjaro, drug interactions might not have been the first question to come to mind. But it’s good to know if it’s safe to combine with other medications you may take. Many interactions involve a drop in your blood glucose (hypoglycemia). But Mounjaro can also potentially interfere with oral medications, including birth control pills.

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Below, we’ll review five notable Mounjaro drug interactions you should know about. But you should share an updated medication list with your prescriber and pharmacist so they can double-check for Mounjaro interactions.

1. Insulin

Some people with Type 2 diabetes use a combination of insulin and other diabetes medications, like Mounjaro, to help manage their blood glucose. However, combining both Mounjaro and insulin can raise the risk of hypoglycemia (blood glucose of less than 70 mg/dL). So extra caution is needed with this combination.

Watch for symptoms of hypoglycemia when administering both Mounjaro and insulin. These can include shakiness, sweating, and a fast heart rate. Hypoglycemia can be life-threatening in severe cases. So it’s important to treat it quickly if it happens to you.

To help prevent hypoglycemia, your endocrinologist may lower your dose of insulin when you first start Mounjaro. Be sure to check your blood glucose as instructed by your prescriber and let them know if you start experiencing low glucose levels.

EXPERT PICKS: WHAT TO READ NEXT

• Can you drink alcohol with Mounjaro? Learn why mixing alcohol and Mounjaro can raise the risk of digestive side effects.

• What does Mounjaro feel like? Real people share their experiences with Mounjaro, which can be beneficial for many people living with Type 2 diabetes.

• What side effects can you expect? Learn about Mounjaro’s side effects — from diarrhea to hair loss — and how to manage them.

2. Sulfonylureas like glipizide

Sulfonylureas are a commonly prescribed group of oral diabetes medications. Examples include glipizide (Glucotrol XL), glyburide (DiaBeta, Glynase), and glimepiride (Amaryl). Taking Mounjaro and sulfonylureas can also raise the risk of hypoglycemia.

Like Mounjaro, sulfonylureas signal your pancreas to release insulin. The difference is that sulfonylureas tell your pancreas to release insulin whether you’ve eaten or not. Taking a sulfonylurea and Mounjaro together may lead to the release of too much insulin. And this can cause hypoglycemia.

As with insulin, Mounjaro and sulfonylureas can still be taken together, if needed. Your endocrinologist may lower your sulfonylurea dose before you start Mounjaro. Be sure to let them know of any notable drops in glucose that happen after starting the combination, or after dose increases.

3. Glinides like repaglinide

Meglitinides (“glinides”) are a less popular group of oral diabetes medications. Examples of glinides include repaglinide and nateglinide. Like sulfonylureas, they tell your pancreas to release insulin. But glinides work faster and their effects are shorter-lived than sulfonylureas.

Similar to the medications listed above, taking Mounjaro and a glinide together can raise the risk of hypoglycemia. If your endocrinologist prescribes both medications for you, they’ll likely adjust your glinide dose when first starting Mounjaro. Let your prescriber know if you start experiencing low glucose levels more frequently after starting both medications.

4. Birth control pills

Mounjaro can make birth control pills less effective, especially when first starting Mounjaro or after dose increases. This can lead to unintended pregnancies or a return of symptoms you’re taking birth control to help manage.

This Mounjaro drug interaction happens because of how the medication works. Mounjaro slows down the movement of food from your stomach to the small intestine. Food that’s delayed in the stomach prevents spikes in your blood glucose and makes you feel full faster and for longer.

A downside to slower digestion is that it can affect how oral birth control is absorbed from your digestive tract. This could mean less medication is absorbed than what’s supposed to be, potentially causing birth control to be less effective. This interaction is most significant when first starting Mounjaro and shortly after any dose increases.

Mounjaro can also cause a number of digestive-related side effects, such as vomiting and diarrhea. Vomiting shortly after a dose of birth control can prevent proper absorption. Diarrhea — particularly diarrhea that continues for 2 days or longer — can also prevent full absorption.

Non-oral methods of birth control, such as the patch or ring, may be better options, as they’re not affected by Mounjaro. You can also use a barrier method, such as condoms. These alternative birth control options should be used for the first 4 weeks after starting Mounjaro and for 4 weeks anytime your dose increases.

5. Other oral medications

Delayed stomach emptying can also affect the absorption of other oral medications, similar to Mounjaro’s interaction with birth control pills.

This may be concerning if you take medications that are highly sensitive to small changes in dose, like warfarin (Coumadin, Jantoven). Warfarin can cause serious side effects, like blood clots or bleeding, even when slight changes in its levels happen. Your warfarin prescriber may recommend monitoring your blood work more frequently when you start Mounjaro.

Your prescriber or pharmacist can tell you if any medications you take are sensitive to small dose changes. They can also provide you with information on the best way to manage this Mounjaro interaction.

What medicine can you not take with Mounjaro?

You shouldn’t take Mounjaro with other medications that work similarly. Examples include Ozempic (semaglutide) and Victoza (liraglutide). Using Mounjaro with these medications can raise your risk of side effects, such as nausea, vomiting, and diarrhea.

Other examples of medicines you shouldn’t take with Mounjaro include:

• Wegovy (semaglutide)

• Rybelsus (semaglutide)

• Trulicity (dulaglutide)

• Saxenda (liraglutide)

• Byetta (exenatide)

• Bydureon BCise (exenatide)

• Zepbound (tirzepatide)

Talk with your endocrinologist if you’re not achieving your desired results with Mounjaro. They can help you explore other options.

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Written by:

Kristine Foley, PharmD

Kristine Foley is a licensed pharmacist with over 13 years of community pharmacy experience. She earned her Doctor of Pharmacy degree from Rutgers University.

Edited by:

Christina Aungst, PharmD

Christina Aungst, PharmD, is a pharmacy editor for GoodRx. She began writing for GoodRx Health in 2019, transitioning from freelance writer to editor in 2021.

Reviewed by:

Joshua Murdock, PharmD, BCBBS

Joshua Murdock, PharmD, BCBBS, is a licensed pharmacist in Arizona, Colorado, and Rhode Island. He has worked in the pharmacy industry for more than 10 years and currently serves as a pharmacy editor for GoodRx.

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