Use of Leucovorin After the FDA Announcement of Its Use for Autism Spectrum Disorders

After national media coverage and a September 2025 White House press conference at which FDA leaders promoted leucovorin as a treatment for autism spectrum disorders, prescriptions among children aged 0–10 rose 14-fold, despite thin evidence of the drug’s effectiveness for treating autism.  This study shows that the FDA’s highly atypical actions in this case had important consequences, including contributing to shortages that may have kept cancer patients from accessing leucovorin for its FDA-approved uses.