Mounjaro (tirzepatide) is a once-weekly injectable medication designed to help individuals with type 2 diabetes manage their blood sugar levels. It’s also known for its potential to promote significant weight loss. If you’ve heard about the impressive effects of Mounjaro, you may be asking, “What does Mounjaro do to your body?”

Mounjaro works by altering the way your body digests food, and while it’s highly effective, it can also lead to some side effects. Not everyone will experience these, and the severity can vary from person to person. However, it’s important to be aware of potential side effects when starting Mounjaro, so you know what to watch for.

What Is Mounjaro (Tirzepatide)?

Mounjaro is the brand name for tirzepatide, a medication that helps control blood sugar in people with type 2 diabetes. It’s also approved under the brand name Zepbound to assist with weight loss for individuals with obesity or weight-related health conditions such as high blood pressure or cholesterol.

While Mounjaro is similar to other injectable diabetes and weight loss medications, such as Ozempic and Wegovy, it has a unique mechanism of action. Like those other medications, Mounjaro works by slowing down food movement through your digestive system, but it also targets two key hormones that play a crucial role in blood sugar regulation and appetite control.

How Does Mounjaro Work in the Body?

Mounjaro mimics the effects of two hormones in your body: glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). These hormones help regulate blood sugar levels, digestion, and appetite.

GLP-1 helps lower blood sugar by increasing insulin production and slowing down digestion, making you feel fuller for longer after meals.
GIP boosts insulin release from your pancreas when your blood sugar rises, ensuring that sugar is converted into energy and doesn’t accumulate in your bloodstream.

In contrast, medications like Ozempic and Wegovy only mimic the effects of GLP-1. By combining both GLP-1 and GIP, Mounjaro offers a unique approach to managing blood sugar and supporting weight loss.

Gastrointestinal Side Effects of Mounjaro

Mounjaro can cause some gastrointestinal (GI) discomfort, primarily because it slows down the movement of food through your gut. These side effects tend to be mild to moderate and usually subside as your body adjusts to the medication. Most people experience them when they first begin taking Mounjaro or when their dose is increased.

Nausea and Mounjaro

During clinical trials, around 22% of Mounjaro users (approximately 1 in 5) reported experiencing nausea, and up to 1 in 10 experienced vomiting. Larger doses tend to increase the likelihood of these side effects.

Tips to Manage Nausea from Mounjaro:

Eat only when you feel hungry, which may be less frequent than before starting the medication.
Stop eating as soon as you feel full, as this may happen faster than expected.
Opt for smaller, more frequent meals rather than three large ones.
Eat slowly to avoid overwhelming your digestive system.
Avoid greasy, fatty foods, which can slow digestion and worsen symptoms.
Try crackers, apples, or mint- or ginger-based drinks about 30 minutes after taking the medication.
For severe nausea or vomiting, avoid drinking with meals. Instead, drink 30-60 minutes before or after meals.
Stay away from strong smells, such as those from cleaning products.

Diarrhea and Mounjaro

Around 12% to 17% of people taking Mounjaro experienced diarrhea during clinical trials.

To Help Prevent or Relieve Diarrhea:

Avoid full-fat dairy, coffee, alcohol, soft drinks, and sports drinks.
Limit high-fiber foods until symptoms improve.
Choose lean protein sources like grilled or baked chicken.
Stick to bland foods like broth, rice, carrots, and ripe peeled fruits.
Drink plenty of water to stay hydrated.

Constipation and Mounjaro

Because Mounjaro slows digestion, constipation can occur in about 1 in 13 users.

Tips for Relieving Constipation:

Drink plenty of fluids, aiming for 91 to 125 ounces of water daily.
Exercise regularly.
Include at least two servings of fiber-rich fruits, vegetables, or whole grains in your diet each day.
Consult your doctor about adjusting your dosage if needed.

Heartburn and Mounjaro

In clinical trials, around 2% of participants (about 1 in 50) experienced heartburn or acid reflux. This could be due to vomiting or slowed digestion.

Preventing or Easing Heartburn:

Avoid spicy, fried, greasy foods, caffeine, and alcohol.
Eat small, slow meals.
Stay upright for a minimum of two hours after eating.
Raise your head and upper body slightly while sleeping.
Sleep on your left side if possible.
Quit smoking, as it can worsen heartburn.

Other Common Side Effects of Mounjaro

In addition to gastrointestinal discomfort, Mounjaro can cause other mild side effects.

Injection Site Reactions

Around 3% of people (about 1 in 30) experience irritation, redness, or pain at the injection site. These reactions usually go away on their own. You can use an ice pack or an over-the-counter anti-inflammatory like ibuprofen for relief.

Dizziness and Mounjaro

Some users feel lightheaded or dizzy after taking Mounjaro, which may be a sign of low blood sugar (hypoglycemia), especially when combined with other blood sugar-lowering medications like insulin or sulfonylureas.

Allergic Reactions and Dizziness

Dizziness can also indicate a serious allergic reaction. If you experience swelling of the face, lips, tongue, or throat, difficulty breathing, rash, or a fast heartbeat, stop taking Mounjaro immediately and seek medical attention.

Mounjaro and Mood Changes

A small number of people report experiencing mood swings, anxiety, depression, or even suicidal thoughts while using Mounjaro. A 2024 study found that only 2% of mood-related reports came from Mounjaro users, with the majority linked to other GLP-1 drugs. Although no definitive link to suicidal thoughts has been established, safety warnings highlight that mood changes could signal hypoglycemia or increased agitation. If you feel unusually nervous, angry, or restless, consult your doctor.

Serious Side Effects of Mounjaro

In rare instances, Mounjaro may cause more serious side effects.

Pancreatitis and Mounjaro

Although rare, pancreatitis (inflammation of the pancreas) has been reported in a small number of Mounjaro users. If you experience sudden, severe belly pain, particularly pain that radiates to your back, seek emergency care immediately.

Thyroid Cancer and Mounjaro

Mounjaro carries an FDA “black box” warning due to studies showing thyroid tumors in rodents. While it’s unclear whether Mounjaro poses the same risk to humans, it is not recommended for those with a history of thyroid cancer. If you experience a lump in your neck, hoarseness, difficulty swallowing, or shortness of breath, contact your doctor.

Stomach Paralysis (Gastroparesis) and Mounjaro

Though rare, medications like Mounjaro that slow digestion can lead to stomach paralysis, a condition where the stomach empties too slowly. Symptoms include bloating, nausea, feeling full after eating, upper belly pain, and undigested food in your stool or vomit. If untreated, stomach paralysis may result in malnutrition and dehydration.

Kidney Disease and Mounjaro

The effects of Mounjaro on kidney function are still under investigation. Some trials have shown a potential for kidney damage, while other research suggests it may prevent kidney disease. Discuss any concerns with your doctor.

Hypoglycemia and Mounjaro

Mounjaro can cause dangerously low blood sugar when used alongside insulin or other blood sugar-lowering medications. If you take insulin or sulfonylureas, work with your doctor to adjust your dosage to avoid hypoglycemia.

Mounjaro and Vision Changes

Mounjaro can cause rapid fluctuations in blood sugar, which may lead to changes in the shape of the eye lenses, resulting in blurry vision. This effect is temporary and should resolve as your body adjusts to the medication. If you have diabetic retinopathy, it’s important for your doctor to closely monitor your eye health, as Mounjaro could potentially worsen the condition temporarily.

Mounjaro and Bowel Obstruction

GLP-1 medications like Mounjaro, which slow digestion, can carry a rare risk of bowel obstruction (ileus). While major studies have not included Mounjaro specifically, they have shown that other GLP-1 drugs may increase the risk of such blockages. A bowel obstruction may occur due to physical blockages, like hardened food, or because of weak intestinal contractions. If untreated, this condition can become life-threatening. Symptoms to watch for include:

Abdominal bloating
Inability to pass gas
Abdominal pain or cramping
Bad breath
Constipation
Diarrhea
Vomiting

If you suspect a bowel obstruction, seek immediate medical attention.

Mounjaro and Gallbladder Issues

In clinical trials, a small percentage (1 in 200) of individuals taking Mounjaro developed acute gallbladder problems, including gallstones or inflammation. Symptoms of gallstones include:

Severe, escalating abdominal pain lasting from 30 minutes to several hours
Pain in the upper back between the shoulder blades or in the right shoulder

Seek immediate medical help if you experience:

Sweating or chills
Low fever
Yellowing of the skin or eyes
Pale-colored stool

Mounjaro and Allergic Reactions

Some users of Mounjaro may experience serious allergic reactions. If you have a history of severe allergic responses, consult with your doctor before starting this medication. Symptoms of an allergic reaction can appear shortly after taking the drug and include:

Rash, itching, or hives
Swelling of the lips, tongue, or throat
Difficulty breathing or wheezing
Dizziness or fainting
Stomach discomfort, bloating, vomiting, or diarrhea
Uterine cramps
A sense of impending doom

If you experience any of these symptoms, seek immediate medical attention.

Long-Term Side Effects of Mounjaro

Given that Mounjaro and similar diabetes treatments are relatively new, their long-term side effects are not fully known. The likelihood of experiencing such effects may vary depending on your overall health. It’s crucial to talk to your healthcare provider about potential risks.

Managing Mounjaro Side Effects

The most frequent side effects of Mounjaro are gastrointestinal (GI) issues. Adjusting your diet and eating habits can help alleviate these symptoms.

Diet Tips:

Opt for boiled, baked, or grilled foods.
Incorporate water-rich foods, such as melons, cucumbers, and bell peppers.
Drink clear liquids.
Avoid fatty, sugary, and spicy foods.
Steer clear of processed foods, dressings, and canned items.

Eating Habits:

Eat slowly and in smaller bites.
Take small sips of liquid and avoid using straws.
Consume smaller, more frequent meals.
Only eat when you’re hungry, and stop when full.
Avoid lying down for a minimum of two hours after eating.
Avoid eating too close to bedtime.
Engage in light activity after meals to aid digestion.
Keep a food diary to identify foods that may trigger GI issues.

Duration of Mounjaro Side Effects

GI symptoms like nausea and decreased appetite typically diminish after a month, though they may return when the dose is increased. The digestion-slowing effect persists for as long as you continue taking the medication.

Who Should Avoid Mounjaro?

Mounjaro should not be used by individuals who have:

A history of thyroid cancer or a strong family history of it
Multiple endocrine neoplasia syndrome II
A severe allergic reaction to the medication or its ingredients

When to Contact Your Doctor

If your side effects persist despite dietary changes, consult your doctor. They may recommend over-the-counter treatments or adjust your dosage. Seek immediate medical attention for severe side effects, including:

Severe allergic reactions
Symptoms indicating thyroid tumors
Intense abdominal pain

Summary of Mounjaro Side Effects

GI-related side effects are the most common when using Mounjaro, but they typically subside within a few weeks. Although serious side effects are rare, it’s essential to seek medical attention if you notice any alarming symptoms.

Mounjaro Side Effects FAQs

Q: What are the drawbacks of using Mounjaro?
A: Mounjaro can lead to uncomfortable GI side effects and poses risks of more serious complications. It’s essential to discuss the potential risks with your healthcare provider.

Q: What does Mounjaro do to your body?
A: Mounjaro slows digestion, reduces appetite, boosts insulin levels, and lowers blood sugar, which helps manage diabetes and supports weight loss.

Q: Can Mounjaro cause constipation or diarrhea?
A: Yes, constipation and diarrhea are common side effects. These can usually be managed with dietary changes, and they should resolve as your body adjusts to the medication.

Conclusion:

In conclusion, Mounjaro (tirzepatide) is a promising treatment for both type 2 diabetes and obesity, offering significant benefits by regulating blood sugar levels and supporting weight loss. However, as with any medication, it is important to be aware of the potential side effects, particularly gastrointestinal issues such as nausea, diarrhea, and constipation. These side effects are often temporary and can be managed with dietary and lifestyle adjustments. In rare cases, more serious side effects like pancreatitis, thyroid cancer, or gallbladder issues may occur, so it is crucial to monitor your health and consult with a healthcare provider as needed.

For those seeking alternatives to Mounjaro, other medications like Ozempic and Wegovy, which are also GLP-1 receptor agonists, are available and offer similar benefits for weight loss and blood sugar control. These medications, like Mounjaro, work by slowing digestion and regulating appetite, but Mounjaro uniquely combines the effects of two hormones to provide a more comprehensive approach.

If you are considering Mounjaro or similar medications like Ozempic and Wegovy, and are in need of a reliable source for these treatments, Better You Rx offers access to these medications through their pharmacy partner services in Canada. With the ability to access these medications through a trusted referral site, individuals can receive the support they need to manage their health. Always consult with a healthcare provider before starting any new medication to ensure it aligns with your specific health needs.