Is hair loss medication okay?

It's not hair loss, but I have some early symptoms, so I'm 고민ing.

My hair has become very thin and weak. ㅜㅜ

Are hair loss medications effective? And if taken in advance, can they prevent hair loss?

Are there any good foods to prevent hair loss?

The illness I really want to avoid the most... I think it's hair loss. If I get hair loss, I will look even older and probably become depressed.

I really want to prevent hair loss.