A comparison of the effects of nonoxynol-9 and chlorhexidine on sperm motility.

The effects of Nonoxynol-9 and chlorhexidine on sperm motility were compared using the objective Transmembrane Migration Ratio method. These agents were found to be of similar potency in inhibiting sperm motility. The concentrations which reduced sperm motility by 50% (EC50) were 0.205 mg/ml for Nonoxynol-9 and 0.215 mg/ml for chlorhexidine. The implications of these findings in relation to the comparison of the effects of drugs on sperm motility and the development of new contraceptive agents are discussed.