Is Zepbound the Same as Mounjaro? A Clear Comparison

Zepbound and Mounjaro are two names you might hear when talking about weight loss or diabetes treatments. Both come from Eli Lilly and Company and share the same active ingredient, tirzepatide. But are they really the same? This article explains their similarities, differences, and uses in simple terms to help you understand what sets them apart.

What Are Zepbound and Mounjaro?

Zepbound and Mounjaro are injectable medications made by the same company. They both use tirzepatide, a drug that mimics two hormones—GIP and GLP-1—to help your body work better. These hormones play a big role in controlling blood sugar and appetite.

Mounjaro hit the market first, approved in 2022 for type 2 diabetes. Zepbound came later, in 2023, aimed at weight loss for people with obesity or related health issues. While they share the same core, their purposes and approvals differ.

Both are given as a weekly shot under the skin. They come in similar doses, but their labels and marketing focus on different health goals.

The Shared Ingredient: Tirzepatide

Tirzepatide is the key to both drugs. It works by boosting insulin production when your blood sugar rises, slowing digestion, and cutting hunger. This makes it great for managing diabetes and shedding pounds.

In Mounjaro, tirzepatide helps people with type 2 diabetes keep their blood sugar in check. It also often leads to weight loss as a bonus. For Zepbound, the focus shifts to weight loss, though it can still affect blood sugar.

Since the active ingredient is identical, the way they work in your body is the same. The difference lies in how they’re prescribed and promoted.

Approved Uses: Diabetes vs. Weight Loss

Mounjaro is FDA-approved to treat type 2 diabetes in adults. It’s meant to improve blood sugar levels when diet and exercise aren’t enough. Doctors often pair it with other diabetes meds.

Zepbound, on the other hand, is approved for chronic weight management. It’s for adults with obesity (BMI of 30 or higher) or those overweight (BMI of 27 or higher) with conditions like high blood pressure or sleep apnea.

So, Mounjaro targets diabetes control, while Zepbound aims at weight loss. That’s the main split, even though both can help with weight.

Doses and How They’re Taken

Both drugs come in the same dose strengths: 2.5 mg, 5 mg, 7.5 mg, 10 mg, 12.5 mg, and 15 mg. They’re injected once a week using a pen or vial, making them easy to use at home.

For Mounjaro, you start at 2.5 mg for four weeks, then move to 5 mg or higher based on blood sugar needs. The max is 15 mg, but not everyone needs that much.

Zepbound follows a similar path—starting at 2.5 mg, then up to 5 mg, 10 mg, or 15 mg, depending on weight loss goals. The dosing schedule is nearly identical.

How They Work in the Body

Since both have tirzepatide, their effects overlap. They slow how fast food leaves your stomach, so you feel full longer. They also tell your brain you’re not hungry, cutting cravings.

In diabetes, Mounjaro lowers A1C (a blood sugar measure) by a lot—up to 2.3% in studies. It also drops weight, often 15-20 pounds, though that’s not its main job.

Zepbound uses the same action for weight loss, with studies showing losses of 15-21% of body weight at higher doses. It can lower blood sugar too, but that’s a side benefit.

Side Effects: Same Drug, Same Risks

The side effects of Zepbound and Mounjaro are alike because they’re the same medicine inside. Common ones include nausea, diarrhea, and tiredness, especially when starting or raising the dose.

In trials, about 20% of people on either drug felt nausea at first. These issues usually ease up as your body adjusts. Higher doses might bring more discomfort.

Rare but serious risks—like pancreatitis or thyroid issues—apply to both. If you feel sharp stomach pain or notice a neck lump, see a doctor fast.

Effectiveness: What Studies Show

Mounjaro’s studies, like SURPASS, focused on diabetes. People on 15 mg saw A1C drop by 2-2.3% and lost up to 25 pounds over 40 weeks. Weight loss wasn’t the goal, but it happened.

Zepbound’s SURMOUNT trials targeted weight. At 15 mg, people lost 20.9% of their body weight—about 48 pounds—over 72 weeks. The 5 mg dose still cut 15%, or 35 pounds.

The numbers show both work well, just with different focuses. Is Zepbound the same as Mounjaro in results? Pretty close, thanks to tirzepatide.

Table: Key Differences at a Glance

Here’s a quick look at how Zepbound and Mounjaro stack up:

This table highlights their shared roots and distinct paths. The drug is the same; the purpose shifts.

Cost and Insurance Coverage

Both drugs can be pricey without insurance. A month’s supply of Mounjaro or Zepbound pens lists at over $1,000. Lilly’s self-pay vials drop that to $550-$650, depending on dose.

Insurance coverage varies. Mounjaro is often covered for diabetes if medically needed. Zepbound might not be for weight loss unless your plan includes obesity drugs.

Some use Mounjaro “off-label” for weight loss to get coverage, but that’s up to your doctor and insurer. Cost-wise, they’re similar per dose.

Can You Switch Between Them?

Since they’re the same drug, switching from Mounjaro to Zepbound (or vice versa) is possible. A doctor might suggest it if your goals change—like focusing on weight instead of diabetes.

The transition is smooth because the doses and delivery are identical. You’d just need a new prescription and maybe a reason for insurance to approve it.

People with diabetes on Mounjaro might switch to Zepbound if weight becomes the priority. It’s all about what you and your doctor decide.

Off-Label Use: A Common Trend

Mounjaro is sometimes prescribed off-label for weight loss, even though it’s for diabetes. Doctors see its weight-dropping power and use it like Zepbound before Zepbound existed.

Zepbound isn’t typically used off-label for diabetes since Mounjaro already covers that. But both can cross over in real-world practice.

This overlap blurs the lines. Is Zepbound the same as Mounjaro in use? Often, yes, depending on the doctor’s plan.

Availability and Supply in 2025

Both drugs faced shortages after launch due to high demand. By April 2025, Eli Lilly has ramped up production. Most doses are now easier to find at pharmacies.

Zepbound vials, launched in late 2024, help with cost and access. Mounjaro’s supply has stabilized too, especially for diabetes patients.

Check with your pharmacy or LillyDirect for stock. Both are more available now than a year ago.

Talking to Your Doctor

If you’re wondering about Zepbound or Mounjaro, your doctor can clarify what’s best. They’ll look at your health—diabetes, weight, or both—and pick the right one.

Bring up costs, side effects, and goals. They might start you on one and adjust later if needed. It’s all about what fits your life.

They can also explain if insurance will cover it. Open chats lead to smarter choices with these drugs.

Summary

Zepbound and Mounjaro are nearly twins—both use tirzepatide and come in the same doses. Mounjaro tackles type 2 diabetes, while Zepbound focuses on weight loss for obesity or related issues. They work the same way, with similar side effects and results, just with different FDA labels.

Studies show Mounjaro cuts blood sugar and weight, while Zepbound maximizes pounds lost—up to 21% at 15 mg. Cost and access are close too, though coverage depends on your plan. Talk to your doctor to see which fits your needs, as they’re more alike than different.

FAQ

Is Zepbound the same as Mounjaro in ingredients?
Yes, both have tirzepatide as the active ingredient. They work the same way in your body.

Can I use Mounjaro for weight loss like Zepbound?
Yes, doctors sometimes prescribe Mounjaro off-label for weight loss. It’s effective, just not its official use.

Are the side effects different between Zepbound and Mounjaro?
No, they’re the same—nausea, diarrhea, and tiredness are common. It depends on the dose, not the name.

Which costs more, Zepbound or Mounjaro?
They’re priced similarly—over $1,000 for pens, $550-$650 for vials. Insurance coverage varies by use.

How do I know which one is right for me?
Your doctor decides based on your goals—diabetes control for Mounjaro, weight loss for Zepbound. Discuss your needs.