There is a cool movie way back in 1995 called "Dr. Jekyll and Ms. Hyde, starring "Wings" star Tim Daly as Dr Richard Jacks, a male perfumist, who inherits his famous great grandfather's work (Dr. Jacks is the great grandson of Dr. Jekyll of the Jules Verne Jekyll and Hyde story). He experiments on the formula, and ends up transforming into a woman, played by Sean Young (from Ace Ventura: Pet Detective), who calls herself Helen Hyde. The movie also stars Jeremy Piven, who discovers Helen in the shower after Dr. Jacks' first transformation to Helen Hyde is complete. Yes, there is a naked shower scene in this movie. Best quote is from Helen as she comes out of the shower.."Are you going to stare at me, or are you going to hand me that towel?"
Helen at first seems harmless, and very polite, even buying the female receptionist a nice dress on her first shopping outing as Helen Hyde. Helen even buys herself clothes on Dr. Jacks' credit card so she can plan to take over. All is well and good until she starts to take over. She wants Dr. Jacks' body, mind, and soul, and will do anything to those ends, even hurting anyone who appears to be a threat. She even sleeps with Dr. Jacks' supervisors (one played by Harvey Feinstein), and tricks Jeremy Piven's character to splash acid on his face, thinking it is a new colonge she is working on. Yin and Yang clash as Dr. Jacks shifts between his female alter ego Helen Hyde and himself. He discovers that each time he shifts into Helen Hyde, she begins to take more control of the body they share. Helen even smokes, much to Dr. Jacks's chagrin.
There are clips of the transformation scenes on Youtube and one of the behind the scenes from the DVD of the movie.