FDA updates Mounjaro and Zepbound labeling and Medication Guides
Both tirzepatide brands received package insert and Medication Guide updates on the same day, but the FDA records do not say what text was revised.
The FDA approved updates to the prescribing information and Medication Guide for Mounjaro and Zepbound on September 25, 2025, according to the agency's Drugs@FDA database [1][2]. Both brands contain the active ingredient tirzepatide and are held by Eli Lilly and Co. [1][2].
The agency actioned two labeling supplements on the same date. For Mounjaro, the action was supplement S-034 under New Drug Application 215866; for Zepbound, it was supplement S-031 under NDA 217806 [1][2]. In both cases, the FDA lists the supplement categories as "Labeling-Package Insert" and "Labeling-Medication Guide" [1][2]. Each entry links to a label PDF and an approval letter for that supplement [1][2].
What changed inside those documents has not been reported. Drugs@FDA records the action date, the supplement number and the type of filing, but it does not summarize the wording that was added, removed or revised [1][2]. The entries do not say whether the change involved dosing, warnings, side-effect language or other sections of the label, and they do not describe a new safety finding [1][2]. No explanation of the update from Eli Lilly appears in the database entries, and neither entry states that the approved uses of either drug changed [1][2].
Mounjaro was first approved on May 13, 2022, under priority review as a Type 1 new molecular entity [1]. Zepbound was first approved on November 8, 2023, also under priority review [2]. Each application lists 24 products: single-dose pens and autoinjectors from 2.5 mg to 15 mg, and multi-dose KwikPen presentations from 10 mg to 60 mg, all as prescription subcutaneous solutions [1][2].
Both brands had other labeling changes earlier in 2025. Mounjaro supplement S-031 was actioned on May 28, 2025, covering the package insert [1]. Zepbound supplement S-020 was actioned on Feb. 7, 2025, covering the package insert plus the container and carton labels [2].
Why it matters for patients
The categories the FDA used show that both the professional labeling and the patient-facing Medication Guide were updated for each brand [1][2]. The Medication Guide is the document that accompanies a dispensed prescription, so people who refill either drug may see wording that differs from the version they received before [1][2].
Because the FDA records do not describe the change, there is no basis in those records to call the Sept. 25 update either minor or significant [1][2]. The product tables in both entries still list the same strengths, and the entries do not show any product added or removed [1][2]. A labeling change can be approved without any change to how a drug is manufactured, packaged or supplied [1][2].
Patients who want to know whether anything about their own prescription has changed can ask a pharmacist or prescriber to see the current Medication Guide [1][2].
What happens next
The FDA database does not indicate when the next labeling action for either application is expected [1][2]. The label PDFs and approval letters tied to the Sept. 25 supplements are posted with each entry, so the revised documents themselves are available even though the change is not summarized [1][2].
Sources
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