Dr. Jekyll And Sister Hyde (1971)

aka's: Dr. Jekyll & Sister Hyde/Doctor Jekyll and Sister Hyde/Doctor Jekyll & Sister Hyde

Dr. Henry Jekyll (Ralph Bates), in attempting to find a toxin that will wipe out all common diseases, accidentally stumbles upon a formula that transforms him into a gorgeous but evil woman (Martine Beswick). He needs female hormones for his experiments, so a number of London women meet their bloody deaths. Also stars Gerald Sim. (Uncut).