I Monster (1971)

A psychiatrist (Christopher Lee) experiments with a drug that will release people and animals from their inhibitions. When he begins taking the serum himself, he finds himself descending into pure evil. Loosely based on DR. JEKYLL AND MR. HYDE by Robert Louis Stevenson and directed by Stephen Weeks. The characters of Dr. Jekyll and Mr. Hyde are called Dr. Marlowe and Mr. Blake in this adaptation of the Stevenson work. Unlike most of the filmed adaptations of the novel, the film eschews any romantic or sexual interest (though he does murder a prostitute who ridicules his looks) for the title characters and concentrates on the psychological aspects (the doctor is a follower of Freud) of the story. The special effects are minimal, we never see the actual transformation of Marlowe to Blake, just the before and after. Christopher Lee is excellent and doesn't overdo the "monster" aspects of his character and keeps it real. The film has a nice look to it thanks to the art direction team and the lensing of Moray Grant (VAMPIRE LOVERS). The score is by Carl Davis (FRENCH LIEUTENANT'S WOMAN). Filmed in 3D but never released in that format theatrically. With Peter Cushing and Mike Raven.