Saw palmetto for hair loss?

I thinking of taking saw palmetto to aid my hair loss problem, but I'm clueless about whether I should use it orally (oil) and/or Topically (cap). How strong should the dose be: 320mg, 500mg, 3000mg? Also, does Aloe, Arnica,Birch, Burdock, or Catmint stop hair loss? Any other cheap/simple ways to help?