Would things like hair loss medication or hair loss shampoo be effective?

Why does hair loss exist?

I'm curious if things like hair loss medicine actually work.

I heard that things like hair loss shampoos are definitely just for prevention, and that no one has actually seen any effect from them.

So, I'm really curious about the effectiveness of products like hair loss medication!

I do have a Propecia product that an acquaintance recommended to me a while ago, but

I'm curious if this will be effective.