I need your advise.

[MikeyB]

I'm 21 years old, my friend told me my hairline was receding. I can see and feel the different in my hair. I should probably note that my dad is bald. I still have hair on the top of my head(for now). I want to know if It would be best to take action now. The only thing, I don't know what's best to use or if there is even a way to preventing it or slowing down the process.