Propecia and dutasteride both Absolutely killed my sex drive and decreased the amount of semen also...BIG TIME! took it for a couple years but NOT ANYMORE. talked to many other people on it also and they stopped taking it becasue it happened to them also. Every person I talked to that used it has suffered sexual side effects so I guess we must be the 2%! I now take procerine and shampo with nizoral and nioxine(no side effects)