The Food and Drug Administration has approved leucovorin for treating cerebral folate transport deficiency caused by FOLR1 variants, a rare neurological condition marked by low folate in the brain. The agency announced the decision on March 10 and called the approval a major milestone for patients who previously had no approved therapy for this genetic disorder. The approval does not extend to autism.
Leucovorin is widely used in oncology to reduce chemotherapy toxicity by replenishing folic acid in healthy cells. Its new, specific indication is for cerebral folate transport deficiency (CFD) due to FOLR1 mutations. The announcement followed heightened public attention and political statements suggesting the drug might also gain authorization for treating autism. In September 2025, public figures including President Donald Trump and others said the FDA had started a process to allow leucovorin for autism symptom management; the FDA’s March 10 action, however, made no mention of autism. Officials at HHS and the FDA have since emphasized that current evidence is insufficient to support a broad autism approval or to call leucovorin a cure for autism. They have noted that any autism-related benefits observed in research may be limited to improvements in speech for a subset of children and that treatment decisions should be made with a child’s physician.
CFD is extremely rare—estimated at about 1 in 1 million people worldwide, although true prevalence is uncertain. Some reports have suggested a substantial proportion of autistic children show folate-related abnormalities, with figures cited between roughly 38% and 70%. Experts warn these numbers may be overstated because many studies relied on FRAT blood tests, which can be inaccurate. While CFD can raise the risk of developmental delays, seizures, and movement problems and may be linked to autism in some cases, having autism does not necessarily mean a higher likelihood of CFD.
Specialists welcomed the FDA approval for patients with genetically confirmed cerebral folate transport deficiency. Developmental clinicians and FDA leaders described the decision as important relief for affected families. Clinicians note that early intervention—particularly treatment begun before age 2—can produce marked clinical and radiological improvement in CFD.
At the same time, most autism experts and professional organizations say it is premature to recommend leucovorin broadly for autism. Research to date has consisted mainly of small studies, often enrolling fewer than 100 participants and sometimes conducted by the same teams. A subset of trials reported gains in communication and behavior for some children—especially those with CFD or other signs of altered folate metabolism—but limitations in study design, small sample sizes, and, in at least one case, a retraction for data errors weaken confidence in the findings. The American Academy of Pediatrics and the Autism Science Foundation have called for larger, independent trials to determine which patients, if any, benefit and to evaluate long-term safety and effectiveness. An HHS official has expressed a similar view.
Leucovorin can be prescribed off-label, and prescriptions for children rose sharply after the September statements that highlighted its potential. Experts caution that increased public attention and easy access to folate products online risk raising false hope, encouraging premature use, or prompting families to try unproven interventions.
Clinicians advise families to consult trusted medical providers about appropriate testing and treatment. For children who show clinical signs of CFD or have biochemical evidence of folate metabolism abnormalities, targeted evaluation and treatment may be appropriate. For the broader population of autistic individuals, more rigorous research is needed to clarify any benefits, identify which subgroups might respond, and assess long-term safety.