Dr. Jekyll and Mr. Hyde (movie, 2008)

Dr. Henry Jekyll is a well-regarded physician whose evenings are spent researching a rare and sacred Amazonian flower so potent it's said to literally separate the soul, giving life to man's Dark Self. The obsessive experiments to isolate its psychotropic properties happen to coincide with a series of brutal murders gripping the city with fear. Jekyll knows it's no coincidence. While his nights are lost to him, he awakens with bloody mementos and violent memories of the screams of his victims.