FDA adds Mounjaro to the national drug shortage list

The U.S. Food and Drug Administration has added Eli Lilly's Mounjaro (tirzepatide) to its list of drugs in shortage, roughly seven months after the injection was approved for type 2 diabetes ^[1]. Trulicity, Lilly's older diabetes injection and its biggest-selling drug, was added to the same list on Thursday ^[1].

The FDA's posting attributes the problem to increased demand and says pharmacies may see delays in receiving full shipments of the 5-milligram dose through January ^[2]. The agency's site says other doses remain available at this time ^[2]. The University of Utah drug information service, which tracks shortages using reports from pharmacies and providers, reports that the 2.5- and 7.5-milligram doses are also on intermittent backorder ^[2]. In other words, the two trackers do not fully agree on how many strengths are affected.

What Lilly has said

The FDA listings follow comments from the company earlier in the week. "We do expect to see intermittent delays at wholesalers and pharmacies in receiving some Mounjaro doses," Chief Financial Officer Anat Ashkenazi said on a conference call with analysts on Tuesday ^[1].

Part of the complexity is the number of separate products involved: Lilly makes six dosage forms of Mounjaro and four of Trulicity, each of which has to be filled and packaged ^[1]. The company says it is expanding manufacturing capacity for the two drugs at its facility in North Carolina and doubling that capacity by the end of 2023 ^[1].

The commercial stakes are large. Trulicity generated $5.5 billion in the first nine months of this year through Sept. 30, while the company and investors are counting on Mounjaro for future growth ^[1]. Mounjaro was approved for type 2 diabetes in May, and Lilly expects tirzepatide to be cleared for obesity next year, a bigger market ^[1].

Mounjaro is not the only incretin drug with supply problems. Reuters notes that supply issues have also affected Novo Nordisk's Wegovy (semaglutide), though that company says it is working to boost manufacturing capacity as well ^[1].

Why it matters for patients

A shortage listing is the FDA's formal signal that supply is not reliably meeting demand. In practical terms, the current posting points to spotty availability rather than a total absence of the drug: the agency flags the 5 mg dose as the problem strength through January, while the University of Utah service adds 2.5 mg and 7.5 mg as intermittently backordered ^[2]. People who fill prescriptions at a particular pharmacy may find that one strength is missing while another is on the shelf, and that availability changes from week to week and from store to store.

Because Mounjaro is a step-up medicine sold in six separate dosage forms, a gap in a single strength can be disruptive for someone in the middle of a planned dose schedule ^[1]. The sources do not say how long the shortage will last beyond January, how many patients are affected, or how the FDA and Lilly will prioritize particular strengths. Those details are not yet known from the material available here.

It is also worth noting what a shortage listing does not mean. Nothing in these reports describes a safety problem, a recall, or a change to the drug's approved use. The stated cause is demand outpacing supply ^[2].

What happens next

• Through January 2023: The FDA expects pharmacies to see delays in receiving full shipments of the 5 mg dose ^[2].
• By the end of 2023: Lilly says it will double manufacturing capacity for Mounjaro and Trulicity at its North Carolina site ^[1].
• 2023: Lilly anticipates a decision on tirzepatide for obesity, which would add a much larger patient population ^[1].