Never share a KwikPen warning added to both tirzepatide labels

Eli Lilly's drug labels for Zepbound and Mounjaro, both containing tirzepatide, added a new Warnings and Precautions section in January 2026 that tells patients never to share a KwikPen with another person, even if the needle is swapped out first ^[1][2]. The change appears in both labels' "Recent Major Changes" tables under section 5.10, dated 01/2026 ^[1][2].

The wording is nearly identical across both drugs. The Zepbound label states: "Never share a ZEPBOUND KwikPen between patients, even if the pen needle is changed" ^[1]. The Mounjaro label carries the same instruction under the heading "Never Share a MOUNJARO KwikPen Between Patients" ^[2]. Both labels list this as a standalone warning, separate from other precautions like pancreatitis, gallbladder disease, and severe gastrointestinal reactions that were already on the labels ^[1][2].

FDA records confirm the timing. A labeling supplement for Zepbound's underlying new drug application, filed under submission number SUPPL-2, was approved on January 20, 2026, and covered changes to the container and carton labels, the package insert, and the medication guide ^[3]. That submission lines up with the January 2026 date shown in the label's change table ^[1][3].

The reason given in the label itself is brief: sharing a pen, even with a fresh needle, can transmit bloodborne pathogens ^[1][2]. The labels do not spell out which specific infections are of concern or cite case reports, so the underlying data behind the warning is not detailed in these documents.

According to the development summary, a similar warning reached the Wegovy pen label about five months later, but that label text was not part of the sources reviewed for this article, so the exact wording and date on Wegovy's label are not yet confirmed here.

Why it matters for patients

Multi-dose pens like the KwikPen are built to be used by one person for multiple weekly doses, not passed between household members or friends looking to save money or share unused medication. Even when someone changes the needle before each use, the pen's internal mechanism can still carry microscopic amounts of blood or bodily fluid from the first user, which is the mechanism the label is warning about ^[1][2].

This matters especially now, given how many people use these pens for weight management or diabetes and may be tempted to share doses with a partner, roommate, or family member who is also trying a GLP-1 drug. The new label language makes clear that risk exists regardless of needle changes, closing off a common assumption that changing the needle alone makes sharing safe ^[1][2].

The change does not affect dosing, effectiveness, or the drugs' other known side effects, which remain unchanged in these labels: nausea, diarrhea, vomiting, constipation, and injection site reactions are still the most commonly reported adverse effects for both Zepbound and Mounjaro ^[1][2].

What happens next

Both labels were revised again later in 2026, with Mounjaro's label reflecting an August 2026 revision that added other updates, including expanded cardiovascular indication language, and Zepbound's label reflecting an August 2026 revision covering gastrointestinal and diabetic retinopathy warning updates ^[1][2]. Whether Wegovy's label carries the exact same never-share language, and when that update took full effect, is not confirmed in the sources reviewed here and would need to be checked directly against Novo Nordisk's current prescribing information.