Keith Joyce stumbled across leucovorin last December while trying to find ways to improve the life of his 4-and-a-half-year-old autistic grandson, Jose. He spent the next few months researching the drug and speaking to neurologists. In April, he sent his research to Jose’s developmental behavioral specialist, who agreed to prescribe the drug.
In the five months since he began treatment, Jose has gone from being typically nonverbal to babbling constantly.
“Within days I started seeing a difference,” Joyce tells WIRED. Before taking leucovorin, “he struggled with two-word sentences, and last night, I had a three or four minute conversation about family with him.”
Joyce wanted to share his research with others because there were so few resources online, so he started the Leucovorin for Autism group on Facebook in May.
There was some interest in the group initially, and by August around 8,000 people had joined, Joyce says. But then came the news that the Trump administration and US health secretary Robert F. Kennedy Jr. were going to be recommending leucovorin as a possible treatment for autism—the group exploded. In the week following Makary’s announcement, membership of Joyce’s group jumped to almost 60,000 people.
Even before the official announcement was made, tens of thousands of new members had joined based on speculation about the drug.
Then, last month, President Donald Trump pushed baseless allegations that the active ingredient in Tylenol and vaccines may contribute to an autism diagnosis. FDA head Marty Makary announced on September 22 that the agency was approving the use of leucovorin to treat folate deficiency in the brain, a deficiency some people with autism symptoms have.
“Leucovorin is something that has for many years been prescribed off-label for autistic people generally, with inconsistent findings,” says Matthew Lerner, program leader of the Life Course Outcomes research program at the AJ Drexel Autism Institute at Drexel University. “There’s been some small research studies on it to date, also with pretty inconsistent findings. But honestly, we don’t know a lot about it, even from those studies, in terms of what would be an optimal dosage, what would be an optimal time period to be on it.”