A fit thin woman holding a Wegovy injection pen for weight loss

Understanding Mounjaro: Exploring Side Effects and Risks

This article is for individuals interested in Mounjaro, a drug used in medical weight loss treatment. We will discuss its potential side effects, risks, and management strategies.

It is important to understand the potential side effects and adverse reactions associated with taking Mounjaro so you can make sure it is the right drug for your needs.

Understanding Mounjaro and Tirzepatide

Mounjaro (also known by its generic name, tirzepatide) is an injectable diabetes drug that also causes significant weight loss. Currently, Mounjaro is only approved by the Food and Drug Administration (FDA) to treat type 2 diabetes, but its use for weight loss in people without diabetes may be FDA-approved in late 2023.

Mounjaro works by causing your stomach to empty more slowly after you eat, so it suppresses your appetite and causes you to feel more full. Unlike similar medications (such as Ozempic and Wegovy), Mounjaro is a dual agonist that activates both glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) rather than just GLP-1.

Tirzepatide is the active ingredient in Mounjaro. Tirzepatide makes the pancreas release more insulin in response to food, which helps regulate blood glucose levels.

There are many benefits and considerations associated with Mounjaro.

The benefits of Mounjaro include:

  • Improved control of diabetes symptoms
  • Improved blood sugar levels
  • Increased glycemic control
  • Weight loss

However, you should not take Mounjaro if:

  • You are breastfeeding
  • You are pregnant
  • You have a family history of medullary thyroid carcinoma (MTC)
  • You have a family history of multiple endocrine neoplasia syndrome type 2 (MEN2)
  • You have had MTC
  • You have had pancreatitis
  • You plan to become pregnant in the next three months

Mounjaro can negatively impact some oral contraceptives.

Common Side Effects of Mounjaro

As with any medication, Mounjaro can cause side effects. Some side effects of Mounjaro are more common than others, and side effects can range in severity from mild to severe.

Mild side effects should subside on their own over time and are not likely to require medical attention. Some of the more common and mild side effects are:

Some of the more common and mild side effects are:

  • Appetite loss
  • Constipation
  • Diarrhea
  • Nausea
  • Vomiting

Other mild but less common (rare) side effects associated with Mounjaro include:

  • Abdominal pain
  • Abdominal swelling
  • Acid reflux
  • Belching
  • Flatulence
  • Indigestion
  • Mild allergic reaction
  • Mild injection site reactions, such as pain

Mounjaro can also cause serious side effects. Contact your doctor if you experience any serious side effects and call 911 or go to the emergency room if your condition is life-threatening.

Serious side effects of Mounjaro include:

Thyroid C-Cell Tumors and Medullary Thyroid Carcinoma (MTC)

sign that says thyroid cancer

Tirzepatide causes dose-dependent and treatment-duration-dependent thyroid C cell tumors in rats, and it is currently unknown if tirzepatide causes thyroid C cell tumors and medullary thyroid carcinoma (MTC) in humans. You should not take Mounjaro if you have a personal or family history of MTC.

Symptoms of MTC include a mass in the neck, dysphagia (difficulty swallowing), and dyspnea (difficult or labored breathing). MTC can also cause persistent hoarseness of your voice. Routinely checking serum calcitonin or using thyroid ultrasound may be able to provide early detection of MTC if you take Mounjaro.

Multiple Endocrine Neoplasia Syndrome Type 2 (MEN 2)

You should not take Mounjaro if you have a personal or family history of multiple endocrine neoplasia type 2 (MEN 2).

There are two types of MEN 2: MEN 2A and MEN 2B. MEN 2A (sometimes called classical MEN 2A or Sipple syndrome) causes MTC and non-cancerous tumors in the parathyroid glands and adrenal glands. MEN 2B is rare and causes MTC, non-cancerous adrenal gland tumors, and non-cancerous tumors on the lips and tongue and in the digestive tract. MEN 2B does not affect the parathyroid glands. The symptoms you would experience due to MEN 2 would depend on the type of tumor you have.

Parathyroid hyperplasia (primary hyperparathyroidism) causes constipation, fatigue, and kidney stones. It may also lead to memory problems and pain in your joints and muscles. Adrenal tumors (pheochromocytoma) can cause anxiety, headaches, and high blood pressure. Rapid heartbeat is also possible.

MEN 2 is diagnosed through genetic testing, physical exams, and lab and imaging tests. Lab tests used to diagnose MEN 2 include measuring blood calcium, calcitonin levels in your blood, and parathyroid hormone levels. Your doctor may also check your plasma or urine for catecholamines and metanephrines. Imaging tests may include a computerized tomography (CT) scan, magnetic resonance imaging (MRI), or an ultrasound scan.

parathyroid gland, CC BY-SA 4.0 <>, via Wikimedia Commons

Identifying Potential Adverse Reactions

As we discussed, there are common and rare symptoms of side effects due to Mounjaro, and the severity can range from mild to life-threatening. You should take note of any side effects or adverse reactions you experience while taking Mounjaro. It is important to report and discuss any symptoms you have with your doctor so that they are aware of it and can adjust or stop your treatment if needed.

Gastrointestinal Effects and Digestive System Reactions

Mounjaro can have gastrointestinal effects such as acid stomach, heartburn, and stomach discomfort and pain.

If you deal with abdominal pain while taking Mounjaro, taking a warm bath or placing a heating pad on your belly can help relieve this symptom. But if you have severe stomach pain that does not subside or the pain radiates to your back or is accompanied by vomiting, you should seek medical attention because you may have pancreatitis, which is swelling of the pancreas.

Having three or fewer bowel movements in a week indicates constipation. Drinking fluids and getting regular exercise can prevent and relieve Mounjaro-induced constipation. To manage diarrhea caused by Mounjaro, it is important to stay hydrated because diarrhea can lead to dehydration.

Rarely, Mounjaro can also cause gastroesophageal reflux disease (GERD) and acute gallbladder disease. Gallbladder disease causes persistent, sharp stomach pain and may also cause nausea, sweating, or vomiting. Seek immediate medical care if you have these symptoms, as you may need to have your gallbladder removed.

water with lemons

Skin and Allergic Reactions

Mounjaro can cause skin-related side effects, such as eczema (a condition that causes bumpy, dry, itchy skin), rashes, and urticaria (a condition that causes itchy, round, red welts on the skin).

Reactions such as these indicate hypersensitivity to the ingredients in Mounjaro, such as tirzepatide. If you experience severe or persistent skin-related issues while taking Mounjaro, you should let your doctor know. You may need to stop taking Mounjaro.

However, anti-drug antibodies and neutralizing antibodies may reduce hypersensitivity reactions and make it possible for you to continue taking Mounjaro.

Other Adverse Effects and Drug-Induced Symptoms

If you experience a severe allergic reaction to Mounjaro, it can affect your respiratory system and cause your mouth, throat, or tongue to swell, which can make it difficult for you to breathe. Mounjaro has been shown to affect the cardiovascular system, such as by reducing systolic blood pressure.

It is important to monitor serum pancreatic amylase and lipase levels while taking Mounjaro because this medication can cause increases in these measurements.

Some side effects caused by Mounjaro may indicate a serious side effect. For example, nausea, vomiting, and yellow eyes are signs of pancreatitis.


Mounjaro is a prescription drug used to treat type 2 diabetes. It is given by injection once weekly, and it causes significant weight loss.

It is important for you to stay informed about new information regarding Mounjaro and communicate with your healthcare provider about your treatment.

Mounjaro can cause serious health complications, including pancreatitis and thyroid cancer. You and your doctor will need to balance the risks and benefits of treatment with Mounjaro for type 2 diabetes or weight loss.

Work with your doctor to monitor and manage potential side effects due to Mounjaro.

Get In-Home Semaglutide, A Medical Weight Loss Treatment

Lose and maintain a healthy weight with semaglutide injections (the same ingredient in Wegovy and Ozempic) at home. We will evaluate your eligibility and prescribe medication if appropriate. Shipments are delivered directly to your door, saving you time.

Make an appointment by clicking the button below!

Experience Care with ConciergeMD

ConciergeMD offers coverage throughout the United States.