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Parents are scrambling to secure a cheap generic cancer drug for their children after the Trump administration touted it as a potential treatment for autism symptoms in the fall.
“I can’t even tell you how much of an influx we’ve had,” Dr. Richard Frye, a pediatric neurologist who studies the medication, called leucovorin, told The Post. “We can’t schedule anymore patients until 2028.”
Now, with the drug out of reach, some parents are turning to over-the-counter folic acid supplements, which they hope can serve as a substitute — but the move, Frye warned, “may do more harm than good.”
What does folate have to do with autism?
Leucovorin is a prescription drug that has traditionally been used to protect healthy cells during chemotherapy. It’s a form of folate, or vitamin B9, an essential nutrient our bodies need but cannot produce on their own.
Folate is critical for brain development. Research has found that some children with neurodevelopmental disorders, including autism, have low levels in their brains — a condition called cerebral folate deficiency.
This deficiency is often caused by autoantibodies that block folate from reaching the brain. One study found that more than 75% of children with autism carry these antibodies, compared with just 10-15% of kids without the disorder.
Intrigued, Frye began exploring whether leucovorin could bypass this blockage and deliver folate directly to the brain, potentially easing symptoms in some children with autism.
In a 2012 clinical trial, he found that about one-third of children with autism who took the drug twice daily showed significant improvements in speech and language. Side effects like hyperactivity resolved quickly, and no serious adverse events were reported.
Fast forward to September, when federal health officials announced they would update leucovorin’s label to allow its use for children with “cerebral folate deficiency and autistic symptoms,” citing studies like Frye’s.
President Trump even called leucovorin an “amazing” drug and touted it as a potential “answer to autism.” But Frye cautions that it’s not a miracle cure.
“If you’re going to the doctor looking for an autism pill, it doesn’t exist,” he told The Post in March. “But leucovorin has helped a lot of children.”
The Autism Science Foundation does not endorse leucovorin as a treatment for autism, saying in a statement that “more studies are necessary before a conclusion can be reached.”
Still, the announcement — along with stories of previously nonverbal children seemingly starting to speak overnight after taking the drug — sparked a rush of parents trying to get it.
But the barriers to access are high. Some, desperate, have turned to folic acid, a form of vitamin B9 sold over the counter. But Frye warned this is not a substitute.
Why folic acid supplements are not the same at leucovorin
“People don’t understand that vitamins are very complex chemicals and treatment with them is not that simple,” Frye said. “What you’re giving, it’s just like a drug.”
Though both leucovorin and folic acid are forms of B9, there’s a crucial difference. Leucovorin is an active form that the body can use immediately, while folic acid is synthetic and must be converted first.
“Our bodies can only activate about 400 micrograms a day, which is what is in your standard or a little even high dose multivitamin, so that’s OK,” Frye explained.
Leucovorin doses, by contrast, are in milligrams — far higher than standard folic acid supplements.
“I have had parents who’ve gone to neurologists and had the neurologist tell them that [leucovorin] is just like folic acid, so just take a lot of it,” Frye said. “You can’t do that.”
Why is too much folic acid a bad thing?
Too much folic acid can overwhelm the body’s conversion process, leaving unmetabolized folic acid in the blood. In pregnant women, Frye said, studies suggest this could increase the risk of autism in their children.
For kids with cerebral folate deficiency and autism, he explained, “we think that the folic acid will essentially plug the transporter,” making it even harder for the nutrient to reach the brain.
“We actually recommend no folic acid for them,” Frye added, Frye added, noting that while the data isn’t definitive, it could potentially worsen their autism symptoms, including behavioral challenges.
“Folic acid is good to a point, like in your everyday regular supplement. But if you need higher doses of folate because of a folate deficiency or other metabolic issues, you can’t use folic acid,” Frye stressed. “Actually, you may do more harm than good.”
