A dramatic surge in demand for a vitamin pill promoted by Donald Trump and Robert F Kennedy Jr as an 'answer to autism' has been documented in a new study. Amid rising global autism diagnoses, the White House had suggested leucovorin – also known as folinic acid, a form of vitamin B – could be approved by the US Food and Drug Administration (FDA) to treat the neurodevelopmental condition.
In September, Mr Trump described the development as one of the most significant in US medical history. 'I think you're going to find it to be amazing,' he said. 'I think we found an answer to autism.' However, the drug – primarily used to counteract the toxic effects of certain chemotherapy treatments – has not received FDA approval for autism. Instead, it has been authorised for treating cerebral folate deficiency, a rare condition where levels of vitamin B9 in the brain are low, linked to autism in a subset of cases.
New research published in JAMA Network Open indicates that publicity surrounding the drug has fuelled a sharp increase in prescribing. Researchers found that the number of leucovorin prescriptions in the US surged by 2,000 per cent late last year. Joshua Rothman, a clinical assistant professor of paediatrics at UC San Diego School of Medicine and the study's lead author, stated: 'Families of children with autism are often searching for therapies that might improve communication and quality of life – especially when treatment options are limited. What this study shows is how quickly information shared through news coverage, social media and public figures can influence real-world prescribing patterns – even before large clinical trials establish whether a treatment is truly safe and effective.'
Previous small studies and case reports have suggested leucovorin may benefit some autistic children, particularly those with speech difficulties. One widely shared case involved Ryan Baldridge Jr, from Missouri, who was described by his family as 'basically non-verbal' until age four. After an autism diagnosis, Ryan struggled to form sentences and could only repeat words spoken to him. His parents later consulted Dr Richard Frye, an autism specialist who believes folate deficiency may underlie some cases. Tests indicated low folate levels, and he was started on twice-daily doses of leucovorin. According to his family, within weeks he began speaking in full sentences and expressing affection for the first time. 'I had never experienced an unprompted 'I love you' from my son in five years of his life,' his father said. 'It was like an explosion of improvement all happening so quickly. Now you can't shut him up.'
Researchers say such high-profile stories, along with comments from political figures, appear to have driven the surge in demand. The study analysed over 300 million patient records from more than 1,800 hospitals and 41,500 clinics across all 50 states. Focusing on over 838,000 children with autism, researchers tracked prescribing across nearly 12 million outpatient visits between January 2023 and January 2026. For the first two years, prescribing rates remained stable at around 34 prescriptions per 100,000 visits. That changed after a widely viewed media report in January 2025 featuring a child treated with leucovorin, which appeared to trigger an initial rise. By August, prescribing rates had climbed to 225 per 100,000 visits. Following public remarks by Mr Trump and Mr Kennedy Jr, rates surged again, reaching more than 835 prescriptions per 100,000 visits by November 2025.
Rothman noted: 'The timing was striking. The increases began after a widely viewed media story and accelerated again after federal officials publicly discussed the medication. It highlights how rapidly clinical practice can shift when a treatment captures public attention.' The researchers stress that larger, high-quality clinical trials are still needed to determine whether leucovorin is truly effective and for which patients. 'We now have a real-world example of how public attention can accelerate adoption of a therapy before the evidence fully catches up,' Rothman added. 'The next step is making sure we generate the rigorous data needed to help families and clinicians make informed decisions.'
The signs and symptoms of autism
People with autism have trouble with social, emotional and communication skills that usually develop before age three and last throughout a person's life. Specific signs include: reactions to smell, taste, look, feel or sound are unusual; difficulty adapting to changes in routine; unable to repeat or echo what is said to them; difficulty expressing desires using words or motions; unable to discuss their own feelings or other people's; difficulty with acts of affection like hugging; prefer to be alone and avoid eye contact; difficulty relating to other people; unable to point at objects or look at objects when others point to them.
