Zepbound and Mounjaro contain the same active ingredient, tirzepatide, and are both made by Eli Lilly. Their list prices are similar, but what you actually pay depends almost entirely on which condition you’re treating and whether your insurance covers it. In practice, Mounjaro is often significantly cheaper for patients because diabetes medications are far more widely covered by insurance than weight loss medications.
Same Drug, Different Price Tags
Zepbound’s list price ranges from $499 to $1,086 for a 28-day supply, depending on the dose. Mounjaro’s list price falls in a comparable range. Since both medications deliver tirzepatide in identical doses, the sticker prices from the manufacturer are not meaningfully different.
But list price is rarely what you pay. The real cost gap comes down to insurance coverage, and that’s where the two medications diverge sharply.
Why Insurance Makes Mounjaro Cheaper for Most People
Mounjaro is approved for type 2 diabetes, and most commercial and government insurance plans cover diabetes medications as a standard benefit. The typical coverage pathway requires a type 2 diabetes diagnosis, and your insurer may ask for prior authorization showing you’ve tried other diabetes medications first (like metformin) and have recent blood sugar levels on file. But once approved, your copay is often modest.
Zepbound is approved for weight management (and more recently for obstructive sleep apnea in adults with obesity), and weight loss drugs face a much steeper coverage battle. Many insurance plans explicitly exclude weight loss medications. Even when plans do cover Zepbound, they typically require extensive documentation: BMI records spanning 6 to 12 months, evidence of previous weight loss attempts, documentation of related health conditions, and sometimes a specialist referral. Only about 19 percent of large employers offering health benefits covered GLP-1 medications for weight loss as of 2025.
If your insurance covers Mounjaro but not Zepbound, you could be looking at a $25 copay for one and $500 or more out of pocket for the other.
Savings Cards From Eli Lilly
Lilly offers manufacturer savings cards for both medications, but the discounts work differently depending on your coverage situation.
If your insurance covers the medication: Both Zepbound and Mounjaro offer savings cards that bring your copay down to as little as $25 per month. For Zepbound specifically, the card provides up to $100 in monthly savings (or $1,300 per year). Mounjaro’s card works similarly, offering $25 fills for up to a 3-month supply.
If your insurance doesn’t cover Zepbound: Lilly offers a separate savings path. With the single-dose pen, you can pay as low as $499 per month. With the KwikPen (a multi-use format), costs start lower depending on dose:
- 2.5 mg dose: as low as $299 per month
- 5 mg dose: as low as $399 per month
- 7.5 mg through 15 mg doses: as low as $449 per month
These same prices apply if you’re paying entirely out of pocket without any insurance. That’s still a significant monthly expense, but it’s lower than the full list price at higher doses.
Medicare Coverage: A Special Case
Medicare Part D has historically not covered medications prescribed solely for weight loss. That’s changing partially through the Medicare GLP-1 Bridge, a temporary demonstration program running from July 2026 through December 2027. Under this program, eligible Medicare beneficiaries can get Zepbound (and other GLP-1 drugs) for weight loss at a $50 copay per month.
There’s an important catch: if your GLP-1 is prescribed for a condition that Part D already covers, like cardiovascular risk reduction or obstructive sleep apnea, you wouldn’t qualify for the Bridge program. You’d go through your plan’s normal coverage process instead. Mounjaro prescribed for type 2 diabetes would continue through standard Part D coverage, which generally offers more favorable cost-sharing than paying for a weight loss medication out of pocket.
The Bottom Line on Cost
If you have type 2 diabetes and your doctor prescribes Mounjaro, you’ll likely pay $25 per month with a savings card and insurance. If you’re seeking weight loss treatment with Zepbound and your insurer covers it, you can reach that same $25. The real cost difference hits when insurance doesn’t cover Zepbound, which is the situation for the majority of people, since most plans still exclude weight loss drugs. In that case, you’re looking at $299 to $499 or more per month even with Lilly’s discount programs.
Before assuming one is cheaper, check your specific plan’s formulary. Call the number on your insurance card and ask whether the medication is covered for your diagnosis. That single phone call will tell you more about your actual cost than any list price comparison.