the other day when i came back from my office i noticed that my hair was thinning down on the top of my scalp.then i started thinking as to what my hair would look like if all my hair would lose,as it is there is a barren spot that has started appearing on my head . then my friend who has his own salon told me to try some hair powder? What are the various kind of hair powders in the market that are can be applied so that there is hair renewal? .Does these hair powders have any side effects that can harm my body internally or externally?