Yes, you can use finasteride for which brand name is Propecia for your hair loss prevention. The actual mechanism of finasteride is to reduce miniaturization of the hair follicle and thus reduces hair loss. But for this, finasteride should be used in conjunction with Minoxidil and this is very important as only one of it won't give you expected results. Finasteride is generally recommended in people with hair transplant. Yes, as said on many blogs, it will some side effects, but there are not proved by evidence. You can find more details on it on US FDA website. But, one more interesting things I have heard that finasteride is actually & heavily used in Japan which is probably one of the oldest countries in the world and their gov has approved it. For me, this is quite strange. Still, we always have scope to discuss with our doc before giving over OTC or self-medication.
I was searching on some of the heard clinics in India for my own treatment & found this: Use of Minoxidil & finasteride in Young, 22 year male.
I think it will help you to get some idea