I haven't heard of such a strange side effect of smoking ganja, but if you say that it's not unheard of, then I suppose I'll just take your word for it. I am genetically predisposed to have thick hair in my youth and will suddenly lose it in my mid forties . . . meh.
my hair is thick as hell, but i'm startin to get more n more grey hairs, i've had em since i was 17 n i'm 19 now, they havent gotten any worse really, more but not noticeable unless ur upclose