The short version
Only one company currently supplies this market — there is no backup if it stumbles. The price has fallen 41% in a year, to $6.74 per mL — and generics that get this cheap tend to get abandoned rather than defended. Put together: this is a fragile supply — if anything else goes wrong, there is very little slack to absorb it. Historically, drugs in this position went on to a new shortage within 90 days about 0.5% of the time — roughly 3× the typical drug (0.1%).
The numbers behind every sentence are on this page below — and the Watch button emails you when any of them move.