Netflix acquired the distribution rights for this film from Paramount, when the studio reportedly couldn't figure out how to market the film.
Dr. Horn's former patients are named after characters in horror films: Perry Hobbes after Detective Hobbes in Il tocco del male (1998), Agnes Thorne after Damien Thorn in Il presagio (1976) and Lucius Woodhouse after Rosemary Woodhouse in Rosemary's Baby - Nastro rosso a New York (1968).
Lead actor Charlie Shotwell was 10 years old when this film was shot from late January to March 2018.
Included in the 2015 Blacklist for top unproduced screenplays.