While tough measures against Rohypnol, the best-known date rape drug, have helped curb its use, sexual abusers are now turning to alternatives, leading to a rise in date rape drugs, according to the United Nations drug control agency’s annual report. The UN hopes these alternative drugs, which might be subject to less strict international controls, will be placed on controlled substances lists; the UN is also pushing for safety features like dyes and flavourings, the BBC reports. “These drugs are used so as to tremendously reduce people’s resistance to unwanted sexual activity and then subsequently they might not even remember what happened,” professor Hamid Ghodse of the International Narcotics Control Board said. In one example, London taxi driver John Worboys was found guilty last year of drugging and sexually assaulting female passengers, giving his victims drinks with sedatives. Many only remembered falling asleep, then waking up at home.