Mounjaro side effects: What you need to know before taking tirzepatide

Mounjaro side effects: What you need to know before taking tirzepatide

Like many prescription drugs, Mounjaro has possible side effects. We review these side effects and other potential concerns with taking this medication.

The Found Team
May 31, 2023
5 min read
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Mounjaro®, the brand name for the drug tirzepatide, is a one-of-a-kind medication that’s taken the current diabetes medication world by storm and has proven to have pretty amazing results. 

As Mounjaro’s popularity has skyrocketed, you may have thought about trying it, your doctor has prescribed it, or you’re currently on it. But this doesn’t mean all your questions have been answered about Mounjaro. We’re here to help give you the full rundown on everything you need to know about Mounjaro side effects, like how long they’ll last and what they are.

Let’s talk about Mounjaro drug information, including Mounjaro side effects and how to manage them.

What are the most common side effects of Mounjaro?

The U.S. Food and Drug Administration approved Mounjaro, a glucose-dependent insulinotropic polypeptide (GIP) receptor agonist and glucagon-like peptide-1 receptor agonist (GLP-1), in May 2022 to treat adults with type 2 diabetes. Although it’s FDA approved to treat type 2 diabetes, it’s made waves in the obesity medicine community because of its ability to also cause weight loss.

Despite its FDA approval and effectiveness in weight loss clinical trials, Mounjaro, like many other prescription drugs and GLP-1 weight loss medications, such as Ozempic or Victoza, has some potential side effects to be aware of.

Here’s what you may experience:

  • constipation
  • decreased appetite
  • diarrhea
  • indigestion
  • nausea
  • stomach pain
  • vomiting

Aside from the gastrointestinal side effects of Mounjaro, you want to be aware of a few other possible side effects. They include: 

  • heart rate increase (tachycardia)
  • injection site reactions
  • increased blood levels of pancreatic enzymes amylase and lipase

Are there serious Mounjaro side effects?

Yes. To be completely transparent, there is a risk of more serious side effects, although they’re rare. Talk to your health care provider immediately or go to the hospital if you experience any of the following:

  • severe stomach problems 
  • pancreatitis (inflamed pancreas)
  • hypoglycemia (low blood sugar) 
  • serious allergic reactions 
  • kidney problems (including kidney failure)
  • changes in vision, including diabetic retinopathy
  • gallbladder problems
  • thyroid tumors, including thyroid cancer

Mounjaro warnings

Like the GLP-1 receptor agonists, tirzepatide has an FDA-mandated boxed—or black box—warning for patients with a personal or family history of medullary thyroid cancer (MTC) or who have multiple endocrine neoplasia syndrome type 2 (MEN 2). They should not take Mounjaro as a weight loss shot or to treat type 2 diabetes. 

On top of that, the manufacturer also warns that birth control pills may not work as well while taking Mounjaro, so talk to your health care provider if you’re on an oral birth control pill. Lilly recommends you use alternate forms of contraceptives for four weeks after your initial dose of Mounjaro and four weeks after each dose increase. 

Mounjaro also isn’t meant for those with type 1 diabetes. Tell your health care provider about any other medical conditions you have and ask them for medical advice before taking Mounjaro.

Can I take Mounjaro while breastfeeding or pregnant?

No. Not enough research to show Mounjaro is safe for breastfeeding or pregnant people. So, it’s best not to use Mounjaro if you’re pregnant or planning on becoming pregnant or breastfeeding, as there’s not enough information on if Mounjaro is passed through the breastmilk onto the baby.

How long do Mounjaro’s side effects last?

You're likely wondering, "will Mounjaro side effects go away?" In most clinical trials, patients reported that the side effects were minimized after a few days but returned when their dose was increased. If you find the side effects you’re experiencing unbearable, let your health care professional know so they can offer guidance or switch medications.

Are there Mounjaro long-term side effects?

Tirzepatide was thoroughly researched and tested for side effects and how long they lasted. Based on the research, Mounjaro is safe for extended use, with no long-term Mounjaro weight loss side effects. Of course, as Mounjaro continues to be used and tested, more evidence and research will come to light on how it performs. But, based on what we know now, it’s effective for sustainable weight management and can continue to be used long-term.

Are there Mounjaro drug interactions?

Remember how we mentioned Mounjaro delayed stomach emptying? This can become an issue if you’re taking oral medication—whether it’s a supplement, over-the-counter medication, or prescription drug—or if you’re prescribed a new medication. This is because when Mounjaro slows digestion, it can cause the oral pills you’re taking to be absorbed less effectively, causing them to lose their potency or efficacy in your body.

Chat with your doctor about everything you’re currently taking. Let them know if another health care professional has prescribed a new oral medication for you. They’ll want to be sure the meds you need are working as intended in your body and to ensure you stay healthy.

What happens if you miss a dose?

Try to follow the dosing schedule your health care professional provides you, but if life gets in the way and you accidentally forget to take a dose, take the missed dose as soon as possible within four days of the missed dose. 

Please don’t take two doses of Mounjaro within three days of each other. If you do take too much Mounjaro, go to the hospital and call your health care provider immediately.

Tips for managing Mounjaro side effects

While you may experience the most common side effects, you can manage them while taking Mounjaro with a few helpful tips from the manufacturer:

  • Eat smaller meals—try splitting your three daily meals into four or more smaller ones.
  • Stop eating when you feel full.
  • Avoid fat or fatty foods.
  • Try eating bland foods like toast, crackers, or rice.

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GLP-1 prescriptions, filled through your local pharmacy, are now available as part of Found's weight-loss toolkit. While GLP-1s are effective for weight loss, they are not clinically appropriate for everyone. Eligibility for a GLP-1 is based on a thorough evaluation of your medical history, eating behavior, lab work, and insurance coverage. If a GLP-1 is not appropriate for you, our providers will work with you to determine an effective medication for your health profile.

About Found

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Published date:
May 31, 2023
Meet the author
The Found Team
The Found Team


  • Eli Lilly and Company. 6 Oct 2022. Lilly receives U.S. FDA Fast Track designation for tirzepatide for the treatment of adults with obesity, or overweight with weight-related comorbidities. Lilly News Release.
  • Eli Lilly and Company. 28 April 2022. Lilly's tirzepatide delivered up to 22.5% weight loss in adults with obesity or overweight in SURMOUNT-1. Lilly News Release.
  • Mounjaro. Feb 2023. How to Us, Dosing & Side Effects.
  • Mounjaro. Feb 2023. How to use Mounjaro.
  • Eli Lilly and Company. May 2022. MOUNJARO (tirzepatide) Injection, for subcutaneous use Initial U.S. Approval: 2022. HIGHLIGHTS OF PRESCRIBING INFORMATION.
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