Mounjaro Side Effects

Generic name: tirzepatide

Written by Kristianne Hannemann, PharmD on March 18, 2025.

Important warnings This medicine can cause some serious health issues

Warning: Risk of Thyroid C-Cell Tumors - In rodents, tirzepatide causes thyroid C-cell tumors.

It is unknown whether tirzepatide causes thyroid C-cell tumors, including medullary thyroid carcinoma (MTC), in humans as the human relevance of tirzepatide-induced rodent thyroid C-cell tumors has not been determined.

Tirzepatide is contraindicated in patients with a personal or family history of MTC or in patients with Multiple Endocrine Neoplasia syndrome type 2 (MEN 2).

Mounjaro (tirzepatide) is a medication commonly prescribed for managing type 2 diabetes. While effective, it can cause a range of side effects. This guide will help you understand the potential side effects of Mounjaro, both common and serious, and provide tips for managing them. Always consult your healthcare provider if you experience any symptoms that are severe or persistent.

Common side effects

Common side effects of Mounjaro are generally mild to moderate and include:

• nausea and vomiting,
• diarrhea,
• decreased appetite,
• indigestion,
• constipation, and
• stomach pain.

These side effects are often manageable with simple lifestyle adjustments and over-the-counter remedies.

Serious side effects

Although less common, Mounjaro can also cause more serious side effects that may require immediate medical attention. These include:

• hypoglycemia (especially when combined with insulin or sulfonylureas),
• allergic reactions,
• tachycardia,
• vision changes,
• pancreatitis,
• gallstones, and
• kidney damage.

Additionally, animal studies suggest Mounjaro has the potential to cause thyroid cancer, which may lead to lumps in the throat and difficulty swallowing. It's important to be aware of these potential risks and consult your healthcare provider if you experience any severe symptoms.

This page provides detailed information on each side effect, including its frequency, severity, and tips for management, to help you use Mounjaro safely and effectively.

Common side effects in more detail

Nausea and vomiting

Nausea and vomiting from Mounjaro are common side effects. Nausea occurs in up to 18% of patients, while up to 9% of patients experience vomiting. For most people, the nauseous feeling is mild to moderate. Nausea and vomiting are most common early on during treatment when you are raising your dose up to the maintenance dose. These side effects are more common with higher doses of Mounjaro. If you experience nausea that is severe or persistent, contact your healthcare provider.

Tips for managing nausea and vomiting

• Eat smaller meals throughout the day
• Avoid greasy foods
• Keep yourself hydrated
• Rest after eating
• Avoid lying down after a meal
• Try peppermint or ginger

Mounjaro reviews for nausea and vomiting

Diarrhea

Diarrhea is another common side effect of Mounjaro, with it occurring in up to 17% of patients. For most people, diarrhea is mild to moderate. You may experience frequent, loose, or watery stools after starting Mounjaro. This is most common during the first weeks of taking it, and should get better over time.

Tips for managing diarrhea

• Stay hydrated by drinking plenty of fluids
• Avoid spicy or fatty foods
• Eat smaller meals
• Choose bland foods
• Do not consume products with sweeteners ending in “ol” (sorbitol, mannitol, xylitol)
• Consider over-the-counter antidiarrheals after consulting a healthcare provider

Mounjaro reviews for diarrhea

Decreased appetite

Mounjaro can commonly cause a decreased appetite. In clinical trials, up to 11% of patients reported having a lower appetite. You may feel less hungry after starting Mounjaro. This is because the medication can slow down your digestion and make you feel fuller longer. This is most common during the first several months of taking it, and may get better over time.

Tips for managing decreased appetite

• Try eating smaller meals throughout the day
• Choose nutrient-dense foods
• Keep up a regular exercise routine to stimulate appetite
• Consider supplementing your diet with liquid meals
• Enhance the flavor of your food

Mounjaro reviews for decreased appetite

Indigestion

Mounjaro can cause indigestion. Up to 8% of adults reported experiencing indigestion during clinical trials. You may experience a sensation of having eaten too much food, feel bloated, or have acid reflux. This may happen because Mounjaro slows down stomach emptying. These symptoms are common in the beginning of treatment with Mounjaro, and may improve as you continue to take the medication. Tell your healthcare provider if your symptoms are very bothersome or are not getting better after a few weeks.

Tips for managing indigestion

• Eat smaller, more frequent meals
• Do not lie down right after eating
• Chew your food slowly and thoroughly
• Wear loose-fitted clothing
• Limit caffeine and alcohol

Mounjaro reviews for indigestion

Constipation

Constipation from Mounjaro is another stomach-related side effect you may experience. It occurs in up to 7% of patients. You may have infrequent or difficult bowel movements. It is not clear how long constipation from Mounjaro lasts. If you continue to have constipation you should tell your healthcare provider.

Tips for managing constipation

• Choose foods that are high in fiber
• Exercise regularly
• Stay hydrated
• Maintain a regular toilet routine
• Consider over-the-counter remedies after consulting a healthcare provider

Mounjaro reviews for constipation

Stomach pain

Another common side effect from Mounjaro is stomach pain, with it occurring in up to 6% of patients. You may experience discomfort or cramping in the stomach area. It is most common to experience stomach pain during the first few months of treatment with Mounjaro. This side effect may get better as your body gets used to the medication. Contact your healthcare provider if stomach symptoms are getting worse or not getting better after some time on Mounjaro.

Stomach pain can be a sign of pancreatitis (inflammation of the pancreas), which requires immediate medical attention. Seek medical attention if you have severe stomach pain with or without vomiting.

Tips for managing stomach pain

• Eat smaller meals more frequently throughout the day
• Steam meats and vegetables instead of frying in butter or oil
• Avoid spicy or rich foods
• Consider over-the-counter pain medications after consulting a healthcare provider

Mounjaro reviews for stomach pain

Serious side effects in more detail

Hypoglycemia

Hypoglycemia (low blood sugar) from Mounjaro is a side effect that is more likely when used with insulin or sulfonylureas. Hypoglycemia occurs in 14% to 19% of patients taking a long-acting insulin and Mounjaro. In patients taking Mounjaro and a sulfonylurea, hypoglycemia occurs in 10% to 14% of patients. Most cases of hypoglycemia are mild or moderate, but severe cases do happen. There were no cases of hypoglycemia in people taking Mounjaro alone during clinical trials.

If you experience symptoms of hypoglycemia (e.g., shakiness, sweating, blurry vision, dizziness), check your blood sugar level. If your blood sugar is low (70 mg/dL or less), take 15 grams of fast-acting carbohydrates. Wait 15 minutes and check your blood sugar level again. Get emergency medical help if you are not responding to fast-acting sugar sources or if your blood sugar level is below 55 mg/dL. Consult your healthcare provider for dose adjustments if needed.

Mounjaro reviews for hypoglycemia

Allergic reactions

Severe allergic reactions to Mounjaro are rare, occurring in 3% of patients. If you experience allergy symptoms such as hives, swelling in your face or throat, or trouble breathing, stop using Mounjaro and seek immediate medical attention.

Mounjaro reviews for allergic reactions

Tachycardia

Some people who take Mounjaro may experience an increase in their heart rate of about 2 to 4 beats per minute. Tachycardia from Mounjaro is rare. Monitor your heart rate, avoid stimulants, and consult your healthcare provider if you experience persistent or severe symptoms.

Mounjaro reviews for heart rate

Vision changes

When blood sugar levels improve too quickly, some people with type 2 diabetes experience a temporary worsening of diabetic retinopathy. If this happens, you may notice blurry vision or other changes to your vision. Contact your healthcare provider if you notice any unusual changes in your vision.

Mounjaro reviews for blurred vision

Pancreatitis

Pancreatitis from Mounjaro is a rare side effect, occurring in less than 1% of patients. Signs of pancreatitis include severe stomach pain and vomiting. Seek immediate medical attention if you experience these symptoms. If you do develop pancreatitis while taking Mounjaro, it is not recommended to start the medication again.

Mounjaro reviews for pancreatitis

Gallstones

Rarely, patients taking Mounjaro experience gallstones. Gallstones occur in less than 1% of patients taking Mounjaro. Contact your healthcare provider for further evaluation if you experience severe abdominal pain, fever, clay-colored stools, or yellowing of your skin or whites of your eyes.

Mounjaro reviews for gallstones

Kidney damage

Rarely, some patients taking GLP-1 receptor agonists have reported kidney injury and worsening kidney function. Because Mounjaro can cause nausea, vomiting, and diarrhea as side effects, you are more likely to become dehydrated. Dehydration can contribute to kidney injury. Make sure to stay hydrated and consult your healthcare provider if you experience symptoms such as swelling or changes in urination.

Mounjaro reviews for kidney issues

Frequently asked questions

• Mounjaro vs Ozempic: Which is right for you?
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• Zepbound Vs Mounjaro: Complete Comparison Guide for Weight Loss and Diabetes Treatment
• Why am I not losing weight on Mounjaro?
• How do Ozempic, Mounjaro, Wegovy, Zepbound compare for weight loss?
• Do Ozempic, Wegovy, Mounjaro & Zepbound cause hair loss?
• How long does it take for Mounjaro to start working?
• Mounjaro side effects you need to be aware of
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Further information

Mounjaro side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer