Mounjaro (Tirzepatide)

Mounjaro is Eli Lilly’s novel Type 2 diabetes drug containing tirzepatide. In clinical trials, it effectively helped regulate blood sugar levels and lower A1C.

In 2022, the U.S. Food and Drug Administration approved Mounjaro for use in adults to help control blood sugar levels and lower insulin sensitivity. Patients should use it coupled with a balanced diet and exercise program for maximal results.

Mounjaro works similarly to other GLP-1 agonist drugs such as Ozempic, and many people experience weight loss while taking it. Mounjaro and Ozempic are each only FDA-approved to treat Type 2 diabetes.

How Does Mounjaro Work?

Mounjaro activates GIP and GLP-1 receptors, which increase insulin sensitivity, prompt the pancreas to release more insulin after eating and prevent the liver from producing excess sugar. This results in more controlled blood sugar levels.

“This mechanism, along with delayed gastric emptying, contributes to blood glucose reduction,” Daniel Neumeier, Ph.D., an immunologist and life sciences specialist at L.E.K. Consulting, told Drugwatch.

Mounjaro’s ability to slow the rate at which food leaves the stomach causes patients to feel full longer. As a result of these mechanisms, many patients report significant weight loss on Mounjaro.

When we eat, our body produces certain chemicals that signal the pancreas to release insulin. This insulin helps regulate our blood sugar levels. Mounjaro helps improve the efficacy of this natural function.

Although it is not FDA-approved for weight loss, Mounjaro can cause significant weight loss. Eli Lilly also produces Zepbound, a GLP-1 with the same active ingredient as Mounjaro, which the FDA approved in 2023 for weight loss in patients diagnosed with obesity or who are overweight.

“Now that Zepbound has been approved for weight management, there really is no reason to take Mounjaro off-label for this purpose,” registered dietitian Catherine Rall told Drugwatch. “It’s always best to take these medications — or any prescription medication — under the supervision of a doctor, and that is best done when you’re taking it as directed.”

Doctors may prescribe Mounjaro for weight loss, but it is an off-label use. Talk to your health care provider about the risks associated with off-label use. Beware of counterfeit products when purchasing medications online or from compounding pharmacies.

The average retail price for Mounjaro is between $1,000 and $1,200 per month if you are uninsured, according to GoodRx Health.

Mounjaro and other GLP-1 class drugs saw sharp price increases in 2024 because of shortages and as off-label weight loss use became popular.

Insurance may cover Mounjaro if you take it to treat Type 2 diabetes. You should check with your insurer for details. But your insurer may not cover tirzepatide if you want to take it for weight loss. For weight loss, your insurance may cover Zepbound since it’s FDA-approved for chronic weight management. Again, check with your insurer.

There are ways to save money on the medication, including using a Mounjaro Savings Card from Eli Lilly. It can reduce your out-of-pocket cost to as little as $25 with insurance.

The recommended starting dose of Mounjaro is 2.5 mg for four weeks to allow the body to adjust to Mounjaro gradually. After four weeks, patients may move up to a weekly dose of 5 mg.

Some patients require higher doses of tirzepatide to achieve optimal results. Doctors may opt to increase medication by 2.5 mg each month until blood sugar levels stabilize. The maximum dose is 15 mg.

How To Take Mounjaro

Patients self-administer Mounjaro once weekly into the abdomen, thigh or upper arm. Mounjaro uses a prefilled, single-use injector pen designed to ensure proper dosing. Weekly shots can be taken at any time of day, with or without meals.

The pens remain safe for 21 days at room temperature, but Mounjaro must be refrigerated for long-term storage. Take missed doses within four days. If it’s been longer, skip the dose and resume on the next scheduled date.

You may experience gastrointestinal side effects while taking Mounjaro. Loss of appetite is also common because of delayed gastric emptying.

“All of the side effects of Mounjaro and Zepbound can be summarized as ‘digestive discomfort,’” Rall said. “They tend to be more severe when you’re first starting on one of these medications, and subside once your body gets used to it.”

Serious Mounjaro Side Effects

More serious Mounjaro side effects include low blood sugar, pancreatitis and issues with other organs.

People who have developed gastroparesis and certain other severe side effects after taking Mounjaro or other GLP-1 drugs may be eligible to file a Mounjaro lawsuit for compensation.

Mounjaro Boxed Warning and Precautions

Mounjaro packaging includes a boxed warning about the risk of thyroid tumors due to tirzepatide. Boxed warnings are the highest level of warnings that the FDA issues.

Avoid taking Mounjaro if you have a personal or family history of thyroid cancer. Report any symptoms of thyroid tumors to your doctor.

GLP-1 receptor agonists like Mounjaro are in high demand and drug shortages are common. Currently, Mounjaro is on the FDA’s drug shortage list for all doses.

“Luckily, compounding pharmacies are available to alleviate the shortage,” Dr. Jonathan Kaplan, a Pacific Heights Plastic Surgery plastic surgeon, told Drugwatch. “But if a patient chooses to only access the name-brand medication through traditional pharmacies, there are many obstacles they’ll have to contend with, in addition to insurance coverage.”

Eli Lilly is addressing the supply shortages, but patients still may need to call multiple pharmacies to find the initial 2.5 mg Mounjaro dosage pen. The FDA lists Eli Lilly’s contact number related to shortages as 800-545-5979.