 It eventually came into effect on 26 May 2016.The Advisory Council on the Misuse of Drugs also told the Government that alkyl nitrites (poppers) were not covered by the law as they were not considered psychoactive, as they affected the muscles and not the central nervous system.The Government accepted this advice and has stated that poppers are not unlawful under the Act, but nevertheless poppers are not listed as exempted substances in Schedule 1 of the Act; however, this is unnecessary because of how they do not affect the central nervous system.