Mounjaro vs Zepbound: what is the difference?

Mounjaro vs Zepbound side by side

Same drug, different label

Both labels list the same initial U.S. approval year for tirzepatide, 2022.^[5][6] Mounjaro is the version labeled for type 2 diabetes, and Zepbound the version labeled for weight management and sleep apnea.^[5][6] The label sets what a drug is approved for, and that drives insurance coverage, savings card rules and Medicare eligibility. Lilly states that Mounjaro is not a weight loss drug.^[2]

The Zepbound label says not to use it with other tirzepatide products or any GLP-1 receptor agonist, so you would take one or the other, never both.^[5]

Mounjaro vs Zepbound for weight loss

Zepbound’s weight results come from trials built to measure weight. In the main 72-week trial of adults without diabetes, average weight loss was 15.0% on 5 mg, 19.5% on 10 mg and 20.9% on 15 mg, against 3.1% on placebo. In a second trial of adults with obesity or overweight and type 2 diabetes, it was 12.8% on 10 mg and 14.7% on 15 mg, against 3.2%.^[5]

Mounjaro’s trials were built to measure blood sugar. Lilly says adults in those studies lost 12 pounds on 5 mg to 25 pounds on 15 mg, while noting that Mounjaro is approved for blood sugar control, not weight loss.^[2] Talk with a clinician about which label fits your diagnosis.

Mounjaro vs Zepbound cost

Lilly sells Zepbound directly at self-pay prices: the KwikPen is $299 for 2.5 mg, $399 for 5 mg and $449 for 7.5 mg to 15 mg if you refill within 45 days ($499 or $699 if you do not).^[1] TrumpRx lists Zepbound at $299 a month and does not list Mounjaro.^[8]

Mounjaro’s list price is $1,112.16 for a 28-day supply, and Lilly says to expect about the full retail price without coverage.^[2] Lilly says Mounjaro is available through LillyDirect on a self-pay basis but does not list that price on its savings page.^[4] The Mounjaro Savings Card works two ways for people with commercial insurance:^[4]

• Plan covers Mounjaro: pay as little as $25 for a 1, 2 or 3 month fill, with up to $150, $300 or $450 off and $1,950 a year.
• Plan does not cover Mounjaro: pay as low as $499 for a 1-month fill, with up to $647 off a month and $8,411 a year.

Both cards expire December 31, 2026, and neither works with Medicare, Medicaid or other government plans.^[1][4] See the Mounjaro cost and Zepbound self pay cost guides for details.

Mounjaro vs Zepbound and Medicare

The Medicare GLP-1 Bridge covers the Zepbound KwikPen only, at $50 a month; the single-dose pen and vials are not covered. Mounjaro is not on the Bridge list.^[3] The Bridge also excludes people with type 2 diabetes, moderate to severe sleep apnea or fatty liver disease, and tells them to ask their Medicare drug plan, which may already cover a GLP-1 drug.^[3]

Mounjaro vs Zepbound side effects

Because they are the same drug, the side effect lists are similar. Reported in at least 5% of people in the label trials:

• Mounjaro: nausea, diarrhea, decreased appetite, vomiting, constipation, indigestion and abdominal pain.^[6]
• Zepbound: nausea, diarrhea, vomiting, constipation, abdominal pain, indigestion, injection site reactions, fatigue, allergic reactions, burping, hair loss and acid reflux.^[5]

Both labels carry a boxed warning about thyroid C-cell tumors in rodents, and both are not for people with a personal or family history of medullary thyroid cancer or MEN 2.^[5][6]

Is tirzepatide more effective than semaglutide?

In the SURMOUNT-5 trial of 751 adults with obesity and no diabetes, average weight loss at 72 weeks was 20.2% on tirzepatide and 13.7% on semaglutide; the trial was open label and funded by Eli Lilly.^[7] See semaglutide vs tirzepatide for the full comparison. Care Anytime members can reach state-licensed doctors by phone or video for non-emergency care through virtual physician access; we do not sell these drugs.