Rogaine is an over the counter solution for hair loss in men and women.  It runs anywhere from $30-50 per month. 

The drug, Minoxidil,  was first made to treat high blood pressure.  It was discovered shortly after that one of the side effects of the drug was its ability to slow down or reverse the balding process.

By applying this externally at about a 2% solution it actually starts to grow hair.  Success rates of Rogaine vary and not everyone experiences re-growth of hair.

Some medical conditions need to be dealt with first before dealing with the hair loss issue.