01/06/2026
A medication has been in the news recently as a treatment for Autism. Leucovorin, also known as folinic acid, is a specific form of the B9 vitamin folate. It is available with a prescription and comes in tablet and intravenous forms. It was originally created to protect healthy cells from the high-dose methotrexate used in cancer treatment. It has also been used to treat low folate levels, which can cause anemia, and for Cerebral Folate Deficiency (CFD). Recently it has been in the news as a treatment for Autism Spectrum Disorder (ASD), since CFD is common in this population.
The internet abounds with stories from parents with seemingly miraculous improvements in their autistic children, particularly for irritability, communication, and muscle movements. Others have reported improvements in behavioral issues, attention, and focus issues.
But it doesn’t help everybody. It seems to help only the ones with folate receptor autoantibodies, which are detected in 58–76 % of children with ASD. Leucovorin bypasses the folate receptor transport system. Even if a child has normal folate levels in their blood, the brain may still be deficient in folate if these antibodies are present.
The Folate Receptor Autoantibody Test (FRAT®) is a blood test that screens for the autoantibodies and is only available with a physician’s order. It tests for both blocking and binding autoantibodies and is not covered by insurance/Medicaid. Results take a few weeks to come back. If a child tests positive, they may be a candidate for Leucovorin. CFD can also be diagnosed through a lumbar puncture, but this is rarely needed.
Leucovorin dosing for ASD/CFD is often 0.5 to 2 mg/kg/day with a max of 50 mg/day.
Dosing is typically started low and titrated up slowly while monitoring for side effects and response.
Leucovorin is the first medication that has shown potentially widespread effectiveness in autism and seeks to reverse one of many metabolic differences seen in this condition, rather than just managing symptoms.
Pediatricians debate leucovorin for autism treatment after Trump’s endorsement of the drug.
