FDA lists Mounjaro 12.5 mg dose as limited through February

Eli Lilly's diabetes drug Mounjaro has limited availability at its 12.5 milligram dose in the United States through February 2024, according to the Food and Drug Administration's website ^[1]. The listing cites an increase in demand ^[1]. Other doses of the injection were listed as available ^[1].

Lilly said it is not holding back shipments. "Eli Lilly continues to ship all doses of Mounjaro to wholesalers," a company spokesperson said in an emailed response ^[1]. The spokesperson added that "the market continues to be dynamic with ongoing fluctuation in demand, so intermittent regional pharmacy stock outages are still possible" ^[1].

Mounjaro's active ingredient is tirzepatide ^[1]. It has been approved for patients with type 2 diabetes to control blood sugar since 2022 ^[1]. Late last year, the FDA also approved the same molecule for weight loss under the brand name Zepbound ^[1]. Tirzepatide belongs to a class of diabetes drugs known as GLP-1 agonists, which are also used off-label and are approved for weight loss ^[1].

High demand for that drug class has triggered supply constraints for Lilly and for Novo Nordisk, whose Wegovy is also affected ^[1]. Wegovy and Zepbound are described as the most effective weight-loss treatments approved to date, competing in a global market estimated to be worth at least $100 billion by the end of the decade ^[1].

Why it matters for patients

The limited-availability flag applies to one specific dose, 12.5 milligrams, not to Mounjaro as a whole ^[1]. A patient whose prescription is written for that dose could still run into a temporary gap at a local pharmacy, because Lilly itself says intermittent regional stock outages remain possible even while it ships every dose to wholesalers ^[1]. Nothing in the company's statement suggests a nationwide halt in distribution ^[1].

Availability can differ by dose, by region and by pharmacy, so a shortage notice on a federal website does not necessarily mean an individual counter will be empty, and it does not predict how long any single patient might wait ^[1].

It has not been reported how many pharmacies have been affected, which regions have seen the most disruption, or whether the 12.5 milligram listing will extend past February 2024 ^[1]. Lilly also has not disclosed what is driving the fluctuation beyond general demand ^[1]. The company has not said whether it expects any other Mounjaro doses to be listed as limited ^[1].

What happens next

The FDA's website is the place where dose-level availability is tracked, and the current listing runs through February 2024 ^[1]. Whether that status changes after February, or spreads to other doses, has not been reported ^[1].

Patients have not been given any new federal guidance about switching doses, and none is described ^[1]. The Reuters report notes that Lilly gained FDA approval for tirzepatide as a weight-loss treatment, sold as Zepbound, in the U.S. late last year, adding a second brand drawing on the same manufacturing supply as Mounjaro ^[1]. How that approval affects supply of either product going forward has not been disclosed ^[1].