Gossypol as a male antifertility agent--why studies should have been continued.

It has been nearly three decades since the beginning of nationwide research into gossypol as a male antifertility agent in China. Several lines of data implicating some side effects of gossypol were published which led to the termination of this area of research in China. The present review re-examines these data and points out the confusion surrounding issues such as hypokalaemia, irreversible azoospermia and other side effects. The prospects and related difficulties for gossypol as a potential male contraceptive are also discussed.