Glycosphingolipids (GSL) are a main constituent of the sperm cell membrane in mammals. Male mice deficient in enzymes involved in GSL synthesis have severely impaired fertility and knockout mice are infertile. Recently, it was demonstrated that administration to mice of an inhibitor of ceramide-specific glycosyltransferase, the first step in the biosynthetic pathway of GSL formation, resulted in reversible infertility without discernable adverse side effects. This inhibitor was Miglustat, which is an alkylated imino sugar. The impact of Miglustat therapy on human spermatogenesis is unknown. If the effects on sperm morphology and motility are similar to those observed in mice, Miglustat or other GSL inhibitors might have potential utility as non-hormonal male contraceptives.