The molecules the nose uses to pick up the scent of cologne have also been found on sperm, suggesting a microscopic courtship takes place in which sperm make their way by following the sweet perfume of human eggs. The startling discovery suggests that a drug that blocks the sperm's ability to sense that enticing aroma could be used as a male contraceptive, said Dr. Robert J. Lefkowitz of Duke University.
"Such a drug could be the ideal contraceptive," Lefkowitz said. It would be likely to have few side effects because the smell receptors on which it would act exist nowhere else in the body except on sperm and in the nose, he said. He presented the results at a science writers' briefing at Duke University.