There are currently 2 proven medicines that can help hair loss male (and maybe some female), especially those who inherited hair loss symptom from their fathers or grandfathers.
1. There is a pill called Propecia, pink colour pill, this is supposed to stimulate new hair growth, in Singapore it can only be prescribed by medical doctors, most doctors are selling it now if you willing to pay, you take 1 pill each day, the side effect is it will affect your sex drive. 1 month of pills cost about S$90+.
2. There is a lotion called Regain, this is supposed to reduce hair loss, in Singapore it can only be bought at pharmacy with a qualified pharmacist (example Guardian), you apply the lotion every morning on the area with severe hair loss. I think there are 2 versions of lotion, 2% and 5% concentration, 1 bottle cost about $70+ and should last 1-3 months, depends on your usage volume. This lotion is poisonous and is stated clearly on the box.
3. Some chinese wll try the traditional chinese herb, example 何首乌, that is supposed to increase your overall body health and hence improve on hair loss.
4. Of course there are those commercial hair loss centres, which is not cheap and the result is not proven, I think its better to try the proven medicine.
But remember both the medicines (Propecia and Regain) will take a few months to see the effect, and if you stop using it then the hair will disappear very soon.