Leucovorin
in Autism Spectrum Disorder
Parent Guide
This page is designed to help parents and families understand how leucovorin (folinic acid) is used in children with Cerebral Folate Deficiency (CFD) & Autism Spectrum Disorder (ASD).
What is Leucovorin?
Leucovorin (also called folinic acid) is a special form of folate that can cross into the brain more effectively than regular folic acid. Some children with ASD have difficulty transporting folate into the brain, especially if they have folate receptor autoantibodies (FRAA). Leucovorin can help improve speech, language, behavior, and attention in certain children with ASD.
Of note, leucovorin is not FDA-approved for the treatment of autism spectrum disorder (ASD). However, multiple studies have shown potential benefits, particularly in improving communication, language, and behavior in some children.
How Long Do Children Stay on Leucovorin?
There is no single 'set time' for how long leucovorin should be used. The decision depends on your child’s response, goals, and tolerance of the medicine:
Clinical trials usually last 3–6 months, but many children benefit beyond that.
If a child is improving and tolerating it well, leucovorin is often continued long-term.
Some families try a trial off the medicine after 6–12 months of stable improvement to see if gains last.
If symptoms worsen after stopping, many children restart and stay on leucovorin for years.
Children who test positive for folate receptor autoantibodies (FRAA) often remain on leucovorin long-term, since the underlying folate issue usually persists.
Is It Safe Long-Term?
Leucovorin is generally safe and well tolerated. Possible side effects include mild gastrointestinal upset, increased activity, or sleep changes (especially at higher doses). Regular check-ins will help ensure that benefits outweigh any side effects.
When to Reassess Use
We will reassess about 2–3 weeks after starting leucovorin, then once a month. Once we find a suitable dose that works for your child, we can follow up every 3 months to monitor progress.
Together, we can decide whether to:
– Continue long-term if your child is improving.
– Try a short break to see if gains remain without it.
– Adjust the dose if side effects occur.
