Seconded, there is no clear line between banned drugs that help you cheat and drugs that fix medical conditions. There are drugs that are allowed if you have a doctor's note, and there are drugs that you can use only up to a certain amount.
Asthma meds for cycling, some of which are steroids, are one of the more popular examples:
https://www.cyclingweekly.com/news/latest-news/the-truth-abo...