A drug that combats attention deficit hyperactivity disorder in children can improve a man’s chances of fathering a child.
Experts have discovered that Ritalin boosts the power and mobility of sperm.
At the moment doctors have almost no prescription medicines that can improve the way sperm swim.
But experts at Cleveland, Ohio, found that sperm mixed with Ritalin became quicker and more likely to penetrate a woman’s egg.
Prof Allan Pacey, of Sheffield University, said: “This could open up the possibility of it being used as a sperm-booster during IVF.”
He added that the link between ritalin and sperm mobility would "certainly be worth investigating as we have almost no prescription medicines that can improve how sperm swim in men".
The findings will be given to the American Society for Reproductive Medicine.
Doctors handed out almost one million prescriptions for the ADHD drug in Britain last year.
Almost one million prescriptions for the drug - used to combat ADHD in children - were handed out last year in the UK.