i've read

"Unfortunately, an aromatase blocker will compromise your gains since it literally stops estrogen from being made. Androgenic related problems can be reduced somewhat by the use of finasteride, which will stop the conversion of testosterone to its more androgenic component DHT. "

on bodybuildingpro.com

and thats seems true because everyone i know who don't used proviron and nolvadex have more mass

could someone explains me why i don't really understand?