What is the difference between Zepbound and Mounjaro?

If you’re exploring GLP-1 medications, you may be wondering about Zepbound versus Mounjaro. These two medications are, in a way, two sides of the same coin. With the same active ingredient — tirzepatide — they work the same way in your body and can have the same impact on your health. And yet, they have different approved uses. Understanding what sets them apart can help you have clear conversations with your healthcare provider about which is the right choice for you. Below, we break down differences between Zepbound and Mounjaro, including how each medication is used, common side effects, dosages, and costs.

What is Zepbound?

Zepbound, a brand-name of tirzepatide, is an injectable GLP-1/GIP prescription medication FDA-approved for chronic weight management. It was approved by the FDA in 2022 for adults with obesity and those who have overweight with at least one weight-related condition, like type 2 diabetes or high blood pressure. In 2024, the FDA also approved Zepbound to treat moderate-to-severe obstructive sleep apnea in adults with obesity.

While Zepbound is considered a GLP-1 weight-loss medication, which is the class of drugs that mimic the naturally occurring GLP-1 hormone, that’s not the entire story. “Zepbound is different from Ozempic and other GLP-1s,” says Dr. Eleanor Yusupov, D.O., assistant professor at New York Institute of Technology’s medical school in Westbury, New York. “That’s because it [mimics] two gut hormones — GLP-1 and GIP — to control blood sugar, increase insulin, decrease glucagon (a hormone that raises blood sugar), slow down food leaving the stomach, and regulate appetite.”

What is Mounjaro?

Mounjaro is another brand name with the active ingredient tirzepatide. This injectable prescription medication was FDA-approved in 2022 to improve glycemic control in individuals with type 2 diabetes. Like Zepbound, Mounjaro mimics the GLP-1 and GIP hormones to help regulate blood sugar, improve insulin production, and promote satiety, says Dr. Andrew Shapiro, M.D., a board-certified general surgery specialist who oversees a medical weight-loss practice in Wellington, Florida.

Do Zepbound and Mounjaro have generic versions?

There are no generic versions of Zepbound or Mounjaro available in the U.S., says Shapiro. Both medications are patented until at least 2036, meaning that only the brand name is currently available.

Key differences between Zepbound and Mounjaro

Because they have the same active ingredient, the main difference between Zepbound and Mounjaro is what they’re FDA-approved for, says Yusupov. “Mounjaro is approved for individuals with type 2 diabetes, while Zepbound is approved for weight loss and obstructive sleep apnea in people with obesity.” Pretty much everything else between these two medications is the same.

Zepbound vs. Mounjaro: uses

While both medications have the same active ingredient, the fact that they have different brand names with different FDA approvals means they are used for separate purposes. Zepbound is approved for two things: chronic weight management for adults with obesity or overweight with another weight-related condition and to treat moderate-to-severe sleep apnea in adults with obesity. Mounjaro is FDA-approved to help treat type 2 diabetes.

Zepbound vs. Mounjaro: dosages and administration

When it comes to dosing, there’s no difference between Mounjaro dosing and Zepbound dosing. Both are taken once a week and are available in six different strengths: 2.5 mg, 5 mg, 7.5 mg, 10 mg, 12.5 mg, and 15 mg. You can get both medications in a prefilled, single-use pen, but “Zepbound is now also available in vials that are less expensive than Zepbound pens, but will require a needle and a syringe,” says Yusupov.

You’ll likely start taking either medication with the 2.5 mg dose for at least four weeks. From there, your doctor may increase your dose by 2.5 mg increments every month, depending on your treatment goals and how your body responds. “Each patient’s experience will be different, and the maintenance dose is decided based on how well the medication is working for them and whether they are experiencing any side effects,” says Yusupov. “For example, if a patient is doing well on their dose of Zepbound and losing weight gradually, we may decide to continue their current dose. On the other hand, if a patient continues to feel hungry or struggles with cravings, then it’s time to adjust the dosage for the next four weeks.”

Effectiveness of Zepbound vs. Mounjaro

You can’t compare Zepbound and Mounjaro’s effectiveness to each other, since one would be measured by weight loss and the other by blood sugar control. In clinical trials, Zepbound, which is the one FDA-approved for weight loss, helped participants lose an average of 20.9% of their weight in a little over a year while semaglutide (Ozempic) led to an average weight loss of 14.9%. As for sleep apnea, one study found that people who took 10 mg to 15 mg doses of Zepbound for 52 weeks cut their sleep apnea episodes nearly in half, likely due in part to reductions in body fat.

When looking at the effectiveness of Mounjaro, a clinical trial found that people with type 2 diabetes who took 5 mg to 15 mg doses of Mounjaro for 40 weeks lowered their A1C levels by up to 2.3% (this compares to an improvement of 1.86% for people taking semaglutide).

Zepbound vs. Mounjaro: cost and insurance coverage

Both medications typically retail for over $1,000 per month without insurance, according to their manufacturer Eli Lilly. A month’s supply of Zepbound costs $1,086 while Mounjaro costs $1,080. If you opt for a vial of Zepbound (which you administer with a needle and syringe), it’s cheaper — costing $349 to $699 per month, depending on your dosage.

Insurance coverage varies and depends on your plan, but because Mounjaro is FDA-approved to treat type 2 diabetes, insurance is more likely to cover some or all of the cost if it's prescribed for that condition, says Shapiro. If you qualify for the Mounjaro Savings Card Program, you could pay as little as $25 for a one-month supply. To be eligible, you’ll need a commercial drug insurance plan, a Mounjaro prescription for an approved use, and not to be enrolled in government-funded insurance.

As a weight loss drug, Zepbound “faces more restrictive coverage,” says Shapiro. “Some plans exclude it entirely.” You may be eligible for the Zepbound Self Pay Journey Program through the manufacturer, which reduces the cost of Zepbound vials by up to $200 per month, depending on the dose.

Zepbound vs. Mounjaro: side effects

With the same active ingredient, these two medications have the same potential for side effects. Fortunately, “they are usually mild and temporary,” says Shapiro. Here’s what to be aware of when considering the side effects of Mounjaro vs. Zepbound:

Zepbound side effects

According to the FDA, common Zepbound side effects include:

• Nausea
• Vomiting
• Diarrhea
• Constipation
• Abdominal pain
• Indigestion
• Injection site reaction
• Hair loss
• Fatigue

Though rare, serious side effects include:

• Pancreatitis
• Low blood sugar
• Kidney injury
• Gallbladder disease
• Severe gastrointestinal reactions
• Worsening of diabetic retinopathy
• Allergic reactions
• Thyroid tumors
• Suicidal behavior and ideation

Visit the manufacturer’s site for a full list of Zepbound side effects.

Mounjaro side effects

Mounjaro has similar side effects, according to the FDA, including:

• Nausea
• Vomiting
• Diarrhea
• Constipation
• Abdominal pain
• Indigestion
• Appetite loss

In rare cases, Mounjaro has been linked to complications like:

• Pancreatitis
• Low blood sugar
• Kidney injury
• Gallbladder disease
• Severe gastrointestinal reactions
• Worsening of diabetic retinopathy
• Thyroid tumors
• Allergic reactions

Visit the manufacturer’s site for a full list of Mounjaro’s side effects.

While you should always touch base with your doctor if you’re experiencing side effects, doing so becomes even more important in certain cases. “Consult a healthcare provider if you’re experiencing severe abdominal pain, changes in vision, or allergic reactions,” adds Shapiro, as these can be signs something more serious is going on.

Zepbound and Mounjaro drug warnings

Before starting either medication, there are several safety considerations to keep in mind. First, “it’s important to monitor for signs of hypoglycemia (low blood sugar), especially if [either drug is] used with other diabetes medications,” says Shapiro. And because both Zepbound and Mounjaro slow stomach emptying, they could impact how well your body absorbs other drugs, including blood thinners, diabetes medications, and even oral contraceptives. The FDA recommends you switch to non-oral alternatives for a month after starting the medication and every time you go up in dose to be safe.

What’s more, “people with a personal or family history of medullary thyroid carcinoma and multiple endocrine neoplasia syndrome type 2 absolutely should not take Mounjaro or Zepbound,” says Yusupov. “These medications are also not for women who are pregnant, breastfeeding, or planning a pregnancy.”

The bottom line

Zepbound and Mounjaro are two brand-name versions of the same drug, tirzepatide. Both are once-weekly injectables that help you control your blood sugar and could result in weight loss, but they’re prescribed for different reasons. Zepbound is approved for weight management and to treat obstructive sleep apnea while Mounjaro is approved to help treat type 2 diabetes. Beyond that difference, Zepbound and Mounjaro are very similar. They both come in six different doses, with new patients starting on the lowest dose and gradually working their way up, and have similar potential side effects, which tend to be mild gastrointestinal issues.