That's because this isn't just some laser pointer that has been encased into a box and had a wrist strap attached to it. The Holy Grail of male contraception is a pill that would be 100% effective in preventing pregnancy but leave a man free to enjoy a full sex life. So far, attempts to accomplish this have been disappointing, having largely focused on getting men to produce non-functioning sperm.
But some drugs used for this purpose produce intolerable side effects and have been abandoned one by one. The team of scientists at Monkish University in Australia used a novel approach. Normally, sperm are moved out of the storage area in the testes (vs defer ens) just before ejaculation.
The scientists bred genetically modified mice that were unable to squeeze the sperm out of the vs defer ens, so they stayed in the storage site. When the mice ejaculated there was no sperm present in other words.
