Suppliers are having trouble meeting demands.

I don’t know the exact reason for adderall, but I noticed it happened after the mislabeling of adderall 15mg generic. 20mg was produced with a 15mg label on it. That was pulled from market and then began a slow cascade of people switching to different manufacturers/strengths resulting in a shortage. Again, this is from my observation. The FDA’s website has more on this.

For the diabetic auto injectors, ozempic being used for its non-FDA indication of weight loss resulted in a shortage resulting in a cascade of events like patients switching to different strengths or trulicity, mounjaro, etc. Now all the manufacturers are having trouble keeping up with demand.