The government promoted a new treatment for autism based on scant evidence. Journalists should cover the fallout.

When President Donald Trump and two of his top health officials — Health and Human Services Secretary Robert F. Kennedy Jr. and Food and Drug Administration Commissioner Marty Makary — touted leucovorin as a potential autism treatment in the fall of 2025, families began seeking prescriptions, ordering tests, and trading advice online before researchers had determined whether the drug actually worked.

What happens to patients when the news of a new treatment travels faster than the evidence? This question was raised by panelists at a Sept. 27 session that was part of the Council for the Advancement of Science Writing’s New Horizons in Science briefings at the ScienceWriters2026 conference in Corvallis, Ore.

Leucovorin, also known as folinic acid, is a prescription form of vitamin B9. It has been used for decades, mostly to manage chemotherapy side effects. Researchers have started to investigate whether leucovorin might help autistic children whose brains have trouble getting enough vitamin B9, or folate. In some children, antibodies called folate receptor autoantibodies (FRAAs) may block one of folate’s routes into the brain. One 2024 study raised the possibility that leucovorin could improve verbal communication in children with high levels of these antibodies.

Although the study was small, and the findings preliminary, Trump’s promotion placed the treatment in the national spotlight. Demand increased immediately.

“It was crazy to watch Facebook groups show up overnight with 50,000-plus desperate parents trying to figure out how to get leucovorin and dietary supplement versions of the prescription form,” said panelist Kevin Klatt, a nutrition scientist and registered dietitian.

The Facebook group “Leucovorin for Autism” grew from about 8,000 members in August to nearly 60,000 in the week after the announcement, according to WIRED. A University of Michigan Medicine–led study published in the New England Journal of Medicine found that the number of leucovorin prescriptions filled for children rose 46% the week of the announcement. By the end of 2025, the weekly rate was 700% higher than at the beginning of the year. Klatt also recalled parents spending “hundreds of dollars” on FRAA testing, hoping to learn whether their children might benefit.

At the time of the announcement, studies of leucovorin in autistic children generally involved fewer than 50 participants and followed them for only a few months. One of the largest randomized trials was retracted in January 2026 after researchers identified data inconsistencies and could not reproduce its findings. In March 2026, the FDA approved leucovorin for a rare form of cerebral folate deficiency, but not for autism, citing insufficient evidence.

By then, thousands of families had already spent months trying to determine whether the drug might help their children. Online, they exchanged information about physicians willing to prescribe it, where to obtain antibody tests, and where to buy folinic acid supplements. These online groups filled a vacuum, offering something clinical trials could not: immediate answers.

But immediacy came with a trade-off.

Parents encountered conflicting dosing advice and accounts of the drug’s effects, WIRED reported. Supplement sellers flooded the Facebook group with ads, seeking to profit from the surge in interest.

Social media became an informal medical-information system while researchers were still asking: Does leucovorin work? Which children, if any, benefit? What dose is appropriate, and what are the risks?

In physicians’ offices, doctors had to explain what preliminary studies could and could not show, interpret antibody tests, and weigh uncertain benefits against adverse effects. Meanwhile, families arrived with expectations shaped by federal officials and online testimonials. Even as they sought answers, clear guidance remained scarce. “Many [families] still feel like they were hung out to dry,” Klatt said.

Klatt argued that journalists often move on too quickly to report the next government announcement before learning what became of people who acted on the last one. “There’s been almost no reporting of [consequences] because we’re chasing down whatever is happening in the day,” he said.

Whether leucovorin ultimately proves useful for some autistic children remains an open question. Klatt urged journalists to pursue another: What happened to the families who sought prescriptions, paid for tests, or relied on online advice before evidence emerged? The leucovorin story, and other stories like it, continue to unfold long after the claim that set them in motion fades from the headlines.