Someperson - let me counsel you
Im a male in my mid, approaching late twenties. I have made myself into a guinea pig for all of the hype out there on hair product. Lets look at the facts:
If there was such a thing as just a simple shampoo that would let your hair grow back and you'd have an afro-puff of hair, dont you think you'd have heard about it by now? (Referring to the shampoos that are supposed to help regrow hair - they dont!)
Its true that keeping your scalp clean with a regular ol' shampoo will keep the sebum out of your hair follicles on your scalp. That much is true. However, the true enemy is DHT - Dihydrotestosterone - is what kills your hair follices and makes your hair thin. After it thins so much guess what happens? Yup, you got it- bye bye hair on my head.
If your hair is thinning and you are alarmed see a doctor. Its no big deal, really! My Dr was more than willing to help me. Its not even embarrassing to talk about (unlike male physicals can be!) lol. Your Dr will rule out any problem (hyper/hypo thyroidism,etc) and make sure its male pattern baldness. I started using Rogaine about 5 years ago, it works. However it irritated my scalp so much it drove me crazy. I have really bad allergies and sensitive skin to boot. I would tell you to try Rogaine first. Use it for 6 months. Take 1 picture at the same time every month and compare it. Use the Rogaine every day, 2x a day, extra strength. If the Rogaine irritates you or for whatever reason is doesnt work your last ray of hope is Propecia. Propecia blocks the DHT in your blood, whilst Rogaine blocks it directly on your scalp. Ive been on propecia for about 7 months now with no side effects and my hair regrowth is just awesome! My bald spot is just about covered with hair, and let me tell you - it was shiny and bald before.
Read through this forum and educate yourself. Dont be afraid to ask questions, and definately dont be afraid to ask a Dr. or friend (who might be in the same situation as you).