At a therapeutic dose, this tends to not be an issue for most people as adults even if they previously had issues. This is due to (honestly) eating better, showering more often, and not having the hormone cocktail of puberty. For this reason, it's pretty safe to start treatment at a low/moderate level and see how you react. It's not hard to adjust a dose, and often times even 10-20MGs a week up or down manages to avoid issues.

About hair-loss:

This is a tough one, because Testosterone at high enough levels does tend to convert into DHT (the main thing that will affect your head hair). This doesn't matter at normal therapeutic doses for most men, but those who are genetically pre-disposed do need to be careful. This can be tackled in 2 ways. By working with a lower dose to start and slowly increasing while monitoring any negative effects (the goal is to get you to where you want to feel good, not put crazy high). The other is with medication. This used to just be Finasteride medication, but honestly we feel that has a lot of other potential negatives for the body. Recently Finasteride shampoo or spray (typically mixed with the active ingredient in Rogaine) has come out with great results and much higher availability. If you want TRT and don't want to worry about hair issues, but don't mind a bit of extra cost/effort, that's definitely the way to go imo.