As male pattern baldness is by far the most common cause for hair loss in male population , topically applied substances need to be controlled for the cosmetic efficacy and the enhancement of life quality .. This sentence is hard to understand. A simpler version with equivalent meaning is the following:
Hereditary hair loss is by far the leading cause of hair loss among the male population . Topically applied substances must therefore be checked for their cosmetic effect and with a view to improving the quality of life .