Leucovorin went from an obscure prescription to a household word in the autism community almost overnight. If you’re trying to work out whether it matters for your child, here is what is known.
What leucovorin is
Leucovorin, also called folinic acid, is a prescription form of folate (vitamin B9). Doctors have used it for decades alongside certain cancer treatments and for some types of anemia. Unlike ordinary folic acid, it can reach the brain by a second route.
Why it is discussed for autism
Some children have trouble moving folate into the brain, a problem called cerebral folate deficiency. In some of them the cause is an antibody that blocks the usual transport route. Because leucovorin can use another route, researchers have tested whether it helps autistic children who have this problem.
What the FDA has approved
In September 2025 the FDA announced that it would move to approve leucovorin for cerebral folate deficiency. The approval that followed, in March 2026, covers a rare inherited form of the condition. It does not name autism. Prescribing leucovorin for autism remains an off-label use.
What the studies show
A few small randomized trials have reported improvements in language in some autistic children, mainly those who test positive for the blocking antibody. The trials are small, and medical groups have said more research is needed before leucovorin can be recommended as an autism treatment. It is not a cure, and it does not help every child.
Side effects and cautions
Leucovorin is generally well tolerated. Some children become more hyperactive or irritable on it, and it can interact with certain seizure medications. It is a prescription drug, so it should only be started and monitored by a prescribing clinician who knows your child’s history. Over-the-counter folate supplements are not the same thing.
Leucovorin at Reign-Bow
We introduced leucovorin as an option for some patients in late 2025. It is considered case by case after medical review, and it never replaces the other parts of a child’s care. If you’d like to know whether it is relevant for your child, ask us at your consultation.
This article is general information, not medical advice. Talk with your own clinician about your child or yourself.