You’ve heard of reports that Leucovorin has improved spoken language in autistic kids, but can it help with nonverbal autistic adults as well?
Anyone who’s familiar with the news relating to the drug Leucovorin and autism has probably already read of at least one account, by a parent, of how their nonspeaking autistic child began saying words after being on this drug for several months.
The appearance of speech in these children can’t definitively be attributed to spoken language that would have eventually developed anyways.
Leucovorin, also called folinic acid, is a reduced form of folate (vitamin B9) that can enter the brain even when normal folate transport is impaired.
It’s been used for decades in oncology and metabolic medicine.
Interest in autism comes from findings that some autistic people have disrupted folate transport to the brain, sometimes due to folate receptor alpha autoantibodies.
Can Leucovorin help autistic adults?
There is currently no direct evidence that this medication might help autistic adults, verbal or nonverbal – but that’s because there’s been no research with the adult autistic population being given this drug.
All meaningful clinical research (as of 2026) on Leucovorin and autism has been conducted in children.
The most cited randomized controlled trial was led by Richard E. Frye and published in Molecular Psychiatry (2016).
That study showed improved verbal communication in autistic kids with spoken language impairment related to folinic acid — compared with placebo, particularly in subjects who tested positive for folate receptor alpha autoantibodies. Adults were not included in this investigation.
Subsequent analyses and reviews by Frye and colleagues, including papers in the Journal of Personalized Medicine in 2018 and 2020, reinforced that the observed benefits appear tied to correcting a metabolic deficiency during development.
These papers explicitly note that the findings can’t be generalized to adults because neurodevelopmental windows have largely closed.
A broader review by Frye et al (CNS Drugs, 2020) stated plainly that these kinds of studies have been limited to pediatric populations.
Quite simply, adult outcomes can’t be documented because there’s been no trials, cohort studies or case series examining nonverbal autistic adults and this medication.
Why Child Results Don’t Automatically Apply to Adults
In kids, improvements often involved developmental language acquisition, which depends on neuroplasticity that is far more limited in adulthood.
Think of neuroplasticity as a blob of wet clay. It can be molded, shaped, formed.
But eventually, the clay hardens and can no longer be manipulated; it’s no longer malleable.
The clay is its softest and wettest during childhood, which is why it’s so much easier for children to learn a new language than it is for adults.
It’s why mastering the violin is pretty much beyond reach if you take your first lesson at 30, vs. begin learning at age five.
Even researchers supportive of Leucovorin emphasize that adult treatment would not be expected to re-create childhood developmental gains.
The drug has had moderate evidence of benefit in a biologically defined subgroup of autistic young kids.
This isn’t to say that at some point, researchers won’t be taking a more dedicated look at what happens when Leucovorin is administered to nonverbal autistic adults in carefully controlled experiments over an extended time period.
