Zepbound vs Mounjaro: is Zepbound the same as Mounjaro?

Is Zepbound the same as Mounjaro?

Yes, chemically. Both labels describe the same active ingredient, tirzepatide, a single peptide that activates the GIP and GLP-1 receptors, and both list the same six strengths: 2.5, 5, 7.5, 10, 12.5, and 15 mg. Both start at 2.5 mg once weekly, use the same 2.5 mg dose steps, carry the same boxed warning for thyroid C-cell tumors seen in rodents, and share the same contraindications, including a personal or family history of medullary thyroid carcinoma or MEN 2. [1] [2]

The two brands exist because FDA approves a drug for specific uses, and tirzepatide’s diabetes and weight management approvals were issued under separate brand names. Mounjaro came first, in May 2022, after the SURPASS diabetes trials; Zepbound followed in November 2023 after the SURMOUNT obesity trials. Each label also says not to combine tirzepatide products with each other or with any other GLP-1 drug. Full evidence for the molecule is on the tirzepatide page. [1] [2]

What is each one approved for?

Zepbound’s weight management approval rests on SURMOUNT-1, where adults with obesity lost 15.0%, 19.5%, and 20.9% of body weight on 5, 10, and 15 mg over 72 weeks versus 3.1% on placebo. Its sleep apnea approval rests on two 52 week SURMOUNT-OSA trials, where the apnea hypopnea index fell by 25.3 and 29.3 events per hour versus 5.3 and 5.5 with placebo. [3] [5] Mounjaro’s cardiovascular indication follows SURPASS-CVOT, in which tirzepatide was noninferior to dulaglutide for heart attack, stroke, and cardiovascular death in 13,165 adults with type 2 diabetes and heart disease (hazard ratio 0.92). [2] [6] For the conditions themselves, see obesity, type 2 diabetes, and obstructive sleep apnea.

Zepbound and Mounjaro doses on the FDA label

Label doses in mg, for reference only. The prescriber sets the dose and schedule.

The schedules are built the same way because the drug is the same: a low starting dose to limit nausea and other gastrointestinal effects, then slow increases. Both labels allow the weekly injection day to change as long as doses are at least 3 days apart. [1] [2]

Pens, vials, and KwikPens

Both brands come in four presentations: a single-dose pen, a single-dose vial, a multi-dose vial that holds 4 doses, and a single-patient-use KwikPen that holds 4 doses. Each is injected under the skin of the abdomen or thigh, or the back of the upper arm when someone else gives the injection, rotating the site each week. The labels ask prescribers to train patients on the exact presentation they receive and say the KwikPen is not recommended for self-injection by people with visual impairment. [1] [2]

The presentation matters for price. The manufacturer’s lowest self-pay prices apply to Zepbound vials and the KwikPen, and the Medicare GLP-1 Bridge covers only the Zepbound KwikPen, not vials or single-dose pens. [10] [14]

How insurance coverage differs

Coverage follows the indication on the prescription, not the molecule. Mounjaro for type 2 diabetes is widely covered by commercial plans and Medicare Part D. Zepbound for weight management is excluded by many employer plans, and standard Part D does not cover drugs prescribed only for weight loss. The sleep apnea indication gives some patients a covered route to Zepbound. [10] [11] [16]

From July 1, 2026 to December 31, 2027, the Medicare GLP-1 Bridge lets eligible Part D enrollees get the Zepbound KwikPen for weight management at a 50 USD monthly copay with prior authorization. People with type 2 diabetes, moderate to severe sleep apnea, or fatty liver disease are excluded from the Bridge because their Part D plan may cover a GLP-1 directly. [14] [15]

What do Zepbound and Mounjaro cost?

Prices were checked on 2026-09-22 and change often. Every channel, including telehealth programs and the historical compounded prices, is on the Zepbound cost page. For how tirzepatide compares with semaglutide on price and results, see Wegovy vs Zepbound.

What the trials behind each label show

Because the molecule is the same, the trial programs support each other. In type 2 diabetes, SURPASS-2 compared tirzepatide 5, 10, and 15 mg with semaglutide 1 mg over 40 weeks: HbA1c fell by 2.01 to 2.30 percentage points versus 1.86, and weight by 7.6 to 11.2 kg versus 5.7 kg. [4] In obesity without diabetes, SURMOUNT-5 compared it directly with semaglutide and found 20.2% versus 13.7% weight loss at 72 weeks. [7]

The side effects are the same kind under either name: mostly nausea, diarrhea, vomiting, and constipation during dose increases, with warnings for pancreatitis, gallbladder disease, and low blood sugar when combined with insulin or a sulfonylurea. In SURMOUNT-1 at 15 mg, nausea affected about 31% of participants versus 10% on placebo. [1] [2] [3] Neither brand is on the WADA Prohibited List. [9]

Can you switch between Zepbound and Mounjaro?

People do move between the brands, usually when a diagnosis or insurance coverage changes, but neither label includes a switching protocol, and the right dose after a switch depends on what you were taking and how you tolerated it. Talk to your prescriber before changing products, and do not use both at the same time. [1] [2]

Compounded tirzepatide is not a lawful stand-in for either brand outside a documented patient specific need: FDA declared the shortage over on December 19, 2024. [8] Our compounded tirzepatide guide explains what changed, and the retatrutide vs tirzepatide comparison covers the investigational triple agonist people often ask about next.

Frequently asked questions

Sources

Label facts come from the Zepbound and Mounjaro prescribing information revised in September 2026. Prices come from the tirzepatide cost record.