Yes - though unlikely; you see, it's all a balancing act. If your estrogen gets too low it will kill your sex drive and ability similar to if estrogen was too get too high. Now I wouldn't think that arimidex would lower one's sex drive while on a cycle of aromatizing steroids as letrozole can do, because of the rate at which arimidex is capable of lower estrogen - it shouldn't lower enough to cause problems. But using arimidex without the concurrent use of aromatizing steroids could very likely cause problems.