We present the case of a 55-year-old white female with no history of liver or gastrointestinal disease, admitted with acute liver failure following a trial of cyproheptadine for appetite stimulation. The patient was managed with supportive care, symptomatic treatment, and discontinuation of cyproheptadine. To our knowledge, this is the first described case of cyproheptadine-induced acute liver failure in over 20 years.