Just curious how one knows that one is allergic to a new drug in a commercial. You have to take it to find out you are allergic, right? The subsequent list of symptoms as reasons not to take it. Do those mean one is allergic? Not to my understanding.

It’s reasonable if one knows one is allergic to related drugs, one is to the new one. Like, say you are allergic to penicillin. You reasonably could be to related drugs.

I feel like most people who are allergic have no idea if they are. Or what symptoms indicate they are.

For instance, I had a chronic cough. A new specialist doctor expressed concern about having this cough for five years. He switched me to a different medication, and the cough improved. I was allergic and had no idea.