Some Mounjaro doses go to limited availability again

Eli Lilly notified the U.S. Food and Drug Administration that the 12.5 milligram dose of Mounjaro, its tirzepatide injection for type 2 diabetes, would be in limited supply through February 2024, according to the FDA's website.^[1] Other doses of Mounjaro remained listed as available at the time.^[1]

The shortage notice came amid what Reuters described as an increase in demand for GLP-1 agonist drugs, a class that includes Mounjaro and that is also used off-label for weight loss even when not approved for that purpose.^[1] A Lilly spokesperson said the company continued to ship all doses of Mounjaro to wholesalers, but added that "the market continues to be dynamic with ongoing fluctuation in demand, so intermittent regional pharmacy stock outages are still possible."^[1]

Mounjaro has been approved in the United States for adults with type 2 diabetes since 2022 to help control blood sugar.^[1] Its active ingredient, tirzepatide, later won FDA approval for chronic weight management under a different brand name, Zepbound, in late 2023.^[1] Reuters noted that Zepbound and Novo Nordisk's Wegovy are considered the most effective weight-loss treatments approved so far, competing in a global market some analysts estimate could reach at least $100 billion by the end of the decade.^[1]

The January 2024 notice was not an isolated event. According to the summary of this development, the pattern of certain Mounjaro doses moving in and out of limited availability repeated through the first half of 2024, as demand continued to outrun Lilly's fill-finish manufacturing capacity, though further specifics on that longer pattern are not detailed in the available source.

Why it matters for patients

For people prescribed Mounjaro for type 2 diabetes, a dose listed as "limited availability" on the FDA's shortage tracker can mean a specific pharmacy may not have that strength in stock, even while the company says it is still shipping product to wholesalers nationwide.^[1] That gap between wholesale shipments and what shows up on a local pharmacy shelf is part of why patients have reported spotty access even when a drug is not formally declared to be in full shortage.

The timing also matters because of how tirzepatide is used. The same active ingredient sold as Mounjaro for diabetes is sold as Zepbound for weight loss, and both draw from the same manufacturing and supply chain.^[1] When demand for one use rises, it can affect availability for the other, since Lilly's fill-finish capacity is shared across the tirzepatide product line.

Patients managing diabetes with a specific Mounjaro dose may need to check with their pharmacy or prescriber about whether their strength is affected, since the FDA's shortage list applies to specific doses rather than the drug as a whole.^[1] The source material does not specify which doses beyond the 12.5 milligram strength were affected in this particular notice, or how pharmacies handled substitutions during the period.

What happens next

The FDA's website listed the 12.5 milligram dose as limited through February 2024, but the underlying development notes that this was one instance in a broader pattern that continued through mid-2024.^[1] The sources provided do not include specific dates for when later doses entered or exited limited availability, or when Lilly's fill-finish capacity was expected to catch up with demand. Patients and pharmacies typically rely on the FDA's shortage database and communications from Lilly for updates on which doses are affected at a given time.