Mounjaro: Everything You Should Know

Mounjaro is a new diabetes medication that lowers blood sugar levels in type 2 diabetics. The medication also causes dramatic weight loss in many people who take it. While it’s only approved for people with type 2 diabetes, the FDA is considering it as a weight-loss drug.

What is Mounjaro?

Mounjaro (generic name tirzepatide) is a recently-approved medication for people with type 2 diabetes. Mounjaro improves glucose (blood sugar) control in adults and is meant to be used along with a healthy diet and regular exercise.

Mounjaro (pronounced mown-JAHR-OH) comes in a pre-filled pen similar to insulin and is injected once per week in your arm, thigh, or abdomen. Some people with diabetes may be instructed by their doctor to use Mounjaro in addition to other diabetes medications, while others will take it alone.

Mounjaro was approved by the Food and Drug Administration (FDA) in May 2023, and they announced that they based their decision on evidence from nine drug trials. These trials were conducted across the globe in 24 countries, and over 5,400 people with type 2 diabetes were given Mounjaro during these clinical trials.

How does Mounjaro work?

Mounjaro is approved by the FDA to help improve blood sugar control in people with type 2 diabetes. In clinical trials, it was shown to lower A1c, which is a test that measures your average blood sugar over the previous three months. In people with diabetes, the clinical trials showed a reduction in A1c of 2%, which is very remarkable.

Mounjaro helps improve blood sugar control by encouraging more insulin secretion, improving your cell’s sensitivity to insulin, and decreasing your appetite by slowing the movement of food through your digestive system. Mounjaro also causes your pancreas to release less of the hormone glucagon, which helps to keep your blood sugar from rising.

Mounjaro is the first of its kind because it’s a drug that targets two molecules, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1). These molecules stimulate the release of insulin, alter the rate of food moving through the GI tract, and suppress hunger signals that the gut sends to the brain. The results are lower blood sugar, less hunger, and weight loss.

Mounjaro side effects

Mounjaro, like all medications, can cause side effects. The most common side effects that trial participants taking Mounjaro experienced included:

• Nausea
• Vomiting
• Decreased appetite
• Abdominal pain
• Indigestion
• Constipation
• Diarrhea

Many of the study participants reported that the common side effects, like nausea, occurred when the dose was given, and improved over time. A small percentage (3–6.6%) of participants had to stop taking Mounjaro due to severe gastrointestinal symptoms.

Some study participants experienced more serious side effects. While these side effects were rare, they did occur and included:

• Hypoglycemia (low blood sugar)
• Allergic reactions
• Kidney problems, including kidney failure
• Severe stomach issues
• Pancreatitis (inflamed pancreas)
• Complications related to diabetic retinopathy (diabetes-related eye disease)

Who shouldn’t take Mounjaro?

Mounjaro can have serious side effects, and the manufacturer states that certain people should not take Mounjaro. The drug has not been tested in children and has not been thoroughly tested in pregnant women. It is unknown if Mounjaro passes into breastmilk.

While poorly controlled diabetes during pregnancy is associated with risks to the baby, Mounjaro may also harm the fetus. Speak with your doctor about whether the benefit of taking Mounjaro during pregnancy outweighs the risks.

The drug manufacturer states that people with certain conditions should not take Mounjaro unless otherwise instructed by their healthcare provider. These conditions include:

• A personal or family history of medullary thyroid carcinoma (thyroid cancer)
• Type 1 diabetes
• Multiple endocrine neoplasia syndrome (MEN 2)
• Allergies to any ingredient in Mounjaro
• Pancreatitis
• Pregnancy or breastfeeding
• Gastrointestinal issues

In studies conducted using rats, Mounjaro led to thyroid tumors, including some that were cancerous tumors. Results of animal studies aren’t always the same in human studies, but at this time, the study authors are unsure of whether using Mounjaro will increase the risk of developing thyroid cancer.

Is Mounjaro a weight-loss drug?

Currently, Mounjaro is only approved by the FDA as a medication for people with type 2 diabetes. It is not approved simply for weight loss, and your doctor cannot prescribe it for weight loss alone. However, participants taking Mounjaro experienced dramatic weight loss.

Most health scientists agree that any weight loss of more than 5% of your body weight is clinically significant. Participants taking Mounjaro who had both type 2 diabetes and were either overweight or obese lost up to 15.7% of their body weight. Because the weight loss results were so significant, Eli Lily, the company that makes Mounjaro, is conducting drug trials that are testing Mounjaro as a weight-loss drug. The results should be published later this year.

Since Mounjaro is very effective for weight loss, the company is expecting the FDA to approve the medication for weight loss without type 2 diabetes. All medications have side effects and risks, and the FDA approves medications only if the benefits outweigh the risks.

Taking Mounjaro might be a good solution if you are having trouble controlling your blood sugar levels. Before you decide to take the medication, it’s important to think about the side effects and your personal and family history of the disease. Your doctor will be able to discuss the balance of risk and benefit with you.