Male contraception trial proves successful: "A Sydney scientist working on male contraceptives has found further evidence a hormone based treatment can switch on and switch off sperm production. Doctor Peter Lui conducted a trial of the treatment three years ago in Sydney and has now collated the results of trials from the United Kingdom, United States, China, Indonesia and Melbourne. He has found a 100 per cent success rate with the injections and pills of male hormones, which prevent sperm production. Doctor Lui says all the studies showed male sperm production returned to normal three to four months after the treatment. "The main thing that we worry about long term is the reversibility - so that's no longer an issue," he said. "In terms of acute side effects, there are very few regardless of the formulations. "Now what is unanswered are the long term side effects." Doctor Lui says he hopes the contraceptive will be on the market in five to 10 years."