A medication few people outside medical circles will recognise could soon be under fresh scrutiny, as major trial results are expected this year to assess whether it may benefit some autistic children. Leucovorin, a form of folinic acid, has attracted attention after the US government backed its approval for children with cerebral folate deficiency, a condition thought to be linked to autism in some cases.

That decision, announced last year, prompted unease among clinicians and researchers. Critics argued the move relied on a limited body of evidence, largely drawn from small-scale studies that could not clearly show how effective the drug is, or which children might benefit most. While leucovorin has long been used for other medical purposes, its role in autism remains uncertain.

Greater clarity may arrive in 2026, when findings from the largest clinical trial of leucovorin in autistic children are expected to be published. The study, which has followed hundreds of participants, aims to determine whether the drug can meaningfully improve communication, behaviour or other core features associated with autism, particularly in children with folate-related metabolic differences.

Researchers say the results could help settle a debate that has divided opinion in recent years. If the trial shows clear benefits, it may strengthen the case for targeted use of leucovorin in specific groups. If not, it could reinforce concerns that enthusiasm has run ahead of solid evidence. Either way, the findings are likely to influence future treatment decisions and research priorities on both sides of the Atlantic.