 The Invisible Condom , developed at Université Laval in Québec , Canada , is a gel that hardens upon increased temperature after insertion into the vagina or rectum . In the lab , it has been shown to effectively block HIV and herpes simplex virus . The barrier breaks down and liquefies after several hours . As of 2005 , the invisible condom is in the clinical trial phase , and has not yet been approved for use . 
