Professor Nathan Lawrentschuk, a urologist from Epworth Freemasons and the study’s principal investigator, said the hydrogel dissolves after about two years.Lawrentschuk said he was surprised and overwhelmed by the hundreds of Australian men who registered interest in being participants in the trial.“If it is successful, it could be an absolute game-changer.” Professor Nathan Lawrentschuk, Epworth FreemasonsLawrentschuk said it was also an option for men who wanted to avoid getting a sexual partner accidentally pregnant.He said many couples often now want fertility to be a shared responsibility, and women often rightfully ask: “why is it always my responsibility?”Since the release of the contraceptive pill in 1961, a number of birth control options, including the contraceptive implant and the vaginal ring, have become available for women, while men have been limited to two: condoms and vasectomies.If participants change their minds during the trial and decide they want to conceive, Lawrentschuk said their testicles would still be producing sperm."