Mounjaro vs Zepbound: Same Drug, Two FDA Approvals

Mounjaro and Zepbound contain the same active ingredient — tirzepatide — made by the same company, Eli Lilly. Nothing about either name tells you that. As with Ozempic and Wegovy, what actually separates them is the FDA paperwork: two approvals, filed for two different jobs, at different points in time.

Two approvals, about eighteen months apart

Mounjaro was approved first, in May 2022, as an adjunct to diet and exercise to improve blood sugar control in adults with type 2 diabetes — that remains its only FDA-approved use. Zepbound followed in November 2023, approved specifically for chronic weight management in adults with obesity, or with overweight plus at least one weight-related condition, on the strength of the SURMOUNT-1 trial: up to roughly 21% mean weight loss at the 15 mg dose over 72 weeks¹. Same molecule, filed twice, for two different indications — exactly the Ozempic/Wegovy pattern, under a different manufacturer. See Ozempic vs Wegovy for the semaglutide side of that same story.

The dose ceiling is identical — unlike Ozempic and Wegovy

Here the pattern breaks slightly. Ozempic and Wegovy have different maximum approved doses (2 mg vs 2.4 mg). Mounjaro and Zepbound do not: both are titrated up to a maximum of 15 mg once weekly. The dose schedules are the same; only the approved use printed on the label differs.

Zepbound carries a claim Mounjaro doesn't

In December 2024, the FDA approved Zepbound to treat moderate-to-severe obstructive sleep apnea in adults with obesity — the first drug ever approved specifically for OSA. That approval rests on the SURMOUNT-OSA trials: two phase 3 studies in adults with moderate-to-severe OSA and obesity, in which tirzepatide reduced the apnea-hypopnea index by an estimated 20.0 to 23.8 events per hour more than placebo, depending on whether participants were also using positive airway pressure therapy². Mounjaro's label does not carry this indication — its own outcomes evidence sits in glycemic control for type 2 diabetes, not sleep apnea. The full trial numbers and what the approval actually covers are in Zepbound and sleep apnea.

What is actually identical

The molecule, the manufacturer, the roughly 5-day elimination half-life, and the general GI side-effect profile are the same across both — see GLP-1 side effects for the full label-derived numbers, and how long GLP-1 drugs stay in your system for what that half-life means practically. Off-label prescribing of Mounjaro for weight loss happens in practice, but it is prescribing outside its FDA-approved indication.

What this means for a telehealth prescription

A provider dispensing compounded "tirzepatide" is selling neither brand — see is compounded GLP-1 legit and safe for what that distinction changes about sourcing and quality control. If brand-name access to either Mounjaro or Zepbound specifically matters to you, ask directly; our board tracks brand access as one of six scored dimensions. If the decision is really between tirzepatide and semaglutide rather than between two tirzepatide brand names, semaglutide vs tirzepatide is the comparison that matters, and Wegovy vs Zepbound walks the brand-specific version of that same trade-off. CoreAge Rx carries tirzepatide on our top-scored account, the tirzepatide board ranks the field, and the rest of the Desk's sourced evidence is in the research library.