Nearly 50,000 American children filled a prescription for leucovorin last year, a drug that has never been approved to treat autism, according to research published this week in the New England Journal of Medicine.
The study, led by researchers at University of Michigan Health C.S. Mott Children's Hospital, drew on the IQVIA Longitudinal Prescription Database, which captures the large majority of prescriptions filled in U.S. retail pharmacies. During 2025, that database recorded 150,026 leucovorin prescriptions dispensed to 47,394 children. The weekly number of children filling a leucovorin prescription rose from 734 to 5,858 between the beginning and end of the year, and much of that increase followed a September 2025 federal press conference at which officials described the drug as an effective autism treatment.
