I know that anytime my bf and i aren't doing well I definatley don't have a sex drive. For awhile i thought that there was no hope for me, but lateley we have been doing awesome and i am wanting sex and play time a little too much sometimes.So, for me, a lack of sex drive has to do with how my relationship is going, or if i am just too tired from working out or something. It also can be caused by birth control as well.