From what I have read it will either prevent hairloss or not....
haha
But seriously, everyone is different... genetics, scalp conditions, skin thickness, life style, diet .... so many factors will come into it, best bet is to try it and see how you go. If you are losing lots of hair think about minoxidil (keep in mind if you start it, generally you cant get off it as you will lose all the hair you gained from it) not sure if that still applies to 1x a day compared to 2x a day though.
Remember to massage your scalp daily too, promotes blood flow and good for hair health/growth