Mounjaro and Zepbound are two names you’ve likely heard if you’re exploring weight loss or diabetes treatments. Both are injectable drugs made by Eli Lilly, and they share the same active ingredient, tirzepatide. But are they identical?
The question “Is Mounjaro and Zepbound the same?” pops up often because of their similarities. Knowing their differences can help you make informed choices with your doctor.
This article breaks down their uses, effects, costs, and more. We’ll use simple language to clear up confusion and guide you through the facts.
What Are Mounjaro and Zepbound?
Mounjaro and Zepbound both contain tirzepatide, a drug that mimics GLP-1 and GIP hormones. These hormones control blood sugar, slow digestion, and reduce appetite.
Mounjaro was FDA-approved in 2022 for type 2 diabetes management. Zepbound got approval in 2023 for weight loss in adults with obesity or related conditions.
Both are weekly injections with doses from 2.5 mg to 15 mg. You start low and increase gradually based on your doctor’s plan.
They come in pre-filled pens for easy use at home. The active ingredient makes them work similarly, but their purposes differ.
Key Differences in FDA Approval and Use
Mounjaro targets type 2 diabetes, helping lower blood sugar alongside diet and exercise. It’s not officially for weight loss, though many lose weight using it.
Zepbound is approved for chronic weight management in adults with a BMI of 30+ or 27+ with conditions like hypertension. It’s paired with a reduced-calorie diet.
Doctors sometimes prescribe Mounjaro “off-label” for weight loss. This means using it for a non-FDA-approved purpose, which is common but depends on your case.
Zepbound’s approval focuses on obesity, making it the go-to for weight goals. Insurance often treats them differently based on these labels.
How They Work in the Body
Tirzepatide in both drugs activates receptors that regulate insulin and appetite. This leads to feeling fuller and eating less.
For diabetes, Mounjaro improves glycemic control, often lowering A1C by 1.8-2.4%. It also promotes weight loss as a side effect.
Zepbound leverages the same mechanism for weight loss, with trials showing 15-22% body weight reduction over 72 weeks. The effect depends on dose and lifestyle.
The shared ingredient means their core action is identical. Differences come from dosing schedules and treatment goals.
Here’s a quick comparison of their primary uses:
- Mounjaro: Controls blood sugar; weight loss is secondary.
- Zepbound: Targets weight loss; no diabetes focus.
- Shared: Weekly injections, same dose range.
Effectiveness for Weight Loss
Zepbound shines in weight loss studies. In SURMOUNT-1, users lost up to 52 pounds on the 15 mg dose over 72 weeks.
Mounjaro also leads to significant weight loss, even if it’s for diabetes. SURPASS trials showed 12-25 pounds lost, depending on dose and patient.
Both outperform older drugs like semaglutide in head-to-head data. Zepbound’s edge is its specific design for obesity management.
Lifestyle matters for both. Pairing with healthy eating and exercise boosts results.
Side Effects: Similarities and Differences
Both drugs share side effects since they use tirzepatide. Common ones include nausea, diarrhea, and vomiting, hitting 20-30% of users early on.
Zepbound users report slightly more GI issues due to higher doses for weight loss. These usually ease within weeks.
Rare risks include pancreatitis or gallbladder issues, under 1% for both. Heart rate may rise slightly, by 1-6 beats per minute.
Always report severe symptoms like chest pain to your doctor. Side effects don’t differ much, but Zepbound’s higher doses can feel stronger.
| Feature | Mounjaro | Zepbound |
|---|---|---|
| Active Ingredient | Tirzepatide | Tirzepatide |
| FDA Approval | 2022 (Type 2 Diabetes) | 2023 (Weight Loss) |
| Primary Use | Blood sugar control | Chronic weight management |
| Average Weight Loss | 12-25 lbs (SURPASS trials) | 34-52 lbs (SURMOUNT trials) |
| Cost (No Insurance) | ~$1,000/month | ~$995-$1,000/month |
| Insurance Coverage | Better for diabetes | Varies, often limited |
This table sums up their core differences and similarities.
Cost and Insurance Coverage
Without insurance, both cost around $1,000 monthly. GoodRx coupons can lower Zepbound to $995 or less at some pharmacies.
Mounjaro’s diabetes approval often means better insurance coverage. Plans may cover it fully if you have type 2 diabetes.
Zepbound’s weight loss focus faces stricter insurance rules. Some plans dropped it in 2025, like CVS Caremark, favoring Wegovy instead.
Eli Lilly’s savings card cuts costs to $25 for either if insured and eligible. LillyDirect offers Zepbound vials for $349-$499 for self-pay.
Availability in 2025
The FDA resolved tirzepatide shortages in mid-2025. Pharmacies like CVS, Walgreens, and Amazon Pharmacy stock both drugs reliably.
Mounjaro may be easier to find due to its diabetes priority. Zepbound’s high demand can cause local stock dips.
LillyDirect delivers Zepbound vials to your door, no insurance needed. Mounjaro is mostly pharmacy-based but widely available.
Call ahead or use apps like MedStockCheckr to confirm stock. Refill early to avoid gaps.
Off-Label Use and Doctor Decisions
Doctors often prescribe Mounjaro off-label for weight loss, especially if insurance denies Zepbound. It’s the same drug, so results are comparable.
This approach works if you don’t have diabetes but want tirzepatide’s benefits. Your doctor will assess risks and monitor progress.
Zepbound is preferred for obesity without diabetes. Its approval aligns with weight-focused treatment plans.
Discuss both with your provider. They’ll match the drug to your health goals and coverage.
User Experiences and Insights
On Reddit, users say Mounjaro and Zepbound feel nearly identical. One switched from Mounjaro to Zepbound for better insurance fit and saw no change.
Another lost 30 pounds on Mounjaro off-label, praising its appetite control. Zepbound users report similar success but note stricter prior authorizations.
Some face nausea with both but manage with small meals. Online forums stress working closely with doctors for either.
Practical Tips for Choosing Between Them
Talk to your doctor about your primary goal: blood sugar or weight loss. This guides which drug fits best.
Check insurance coverage early. Mounjaro often wins for diabetes; Zepbound may need appeals for weight loss.
Consider LillyDirect for Zepbound if you’re self-paying. It’s cheaper and convenient for home delivery.
Track side effects and progress. Both require diet and exercise for full effect.
If one’s unavailable, the other can often substitute. Your doctor can adjust the script quickly.
Safety and Long-Term Use
Both drugs need refrigeration for pens or vials. Use within 21 days if kept at room temperature.
Inject weekly in the thigh, belly, or arm. Rotate sites to avoid irritation.
Rare risks like thyroid tumors apply to both. Those with family history of medullary thyroid cancer should avoid them.
Regular check-ins with your doctor ensure safe use. Long-term data shows sustained benefits with proper monitoring.
Which Is Right for You?
Your health condition drives the choice. Mounjaro suits diabetes patients; Zepbound targets obesity without diabetes.
Insurance and cost play a big role. Mounjaro’s coverage is often broader, but Zepbound’s savings options help.
Both deliver strong weight loss. The decision hinges on your medical needs and budget.
Work with your provider to weigh pros and cons. They’ll tailor the plan to you.
Summary
Is Mounjaro and Zepbound the same? They share tirzepatide, delivering similar weight loss and side effects. Mounjaro focuses on diabetes; Zepbound targets obesity.
Differences lie in FDA approval, insurance, and dosing goals. Both are effective, with costs around $1,000 unless covered or discounted.
Talk to your doctor, check coverage, and monitor progress. Either can be a game-changer with the right plan.
FAQ
Is Mounjaro and Zepbound the same drug?
Yes, both use tirzepatide and work similarly. Mounjaro is approved for type 2 diabetes, while Zepbound targets weight loss. Effects and side effects are nearly identical.
Can I use Mounjaro instead of Zepbound for weight loss?
Yes, doctors often prescribe Mounjaro off-label for weight loss. It’s the same active ingredient, but insurance may favor it for diabetes only. Check with your provider.
Are side effects different between Mounjaro and Zepbound?
Side effects like nausea or diarrhea are similar since both use tirzepatide. Zepbound’s higher doses may feel slightly stronger. Most issues ease within weeks.
Which is cheaper, Mounjaro or Zepbound?
Both cost about $1,000 without insurance. Mounjaro may have better coverage for diabetes; Zepbound’s LillyDirect vials start at $349 for self-pay.
Can I switch between Mounjaro and Zepbound?
Yes, since they’re the same drug, switching is often seamless. Your doctor can adjust the prescription based on availability or insurance. Monitor for consistent dosing.