The stimulatory effects of caffeine, theophylline, lysine-theophylline and 3-isobutyl-1-methylxanthine on human sperm motility

The potencies of caffeine, theophylline, lysine-theophylline and 3-isobutyl-1-methylxanthine (IBMX) in stimulating sperm motility have been compared, and we have found IBMX to be significantly more potent than the other three compounds, which did not exhibit significant differences in potency from each other.