What science says about leucovorin, the drug Trump touted for autism

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  Science and Technology on Wed, Sep 24th, 2025 by News 8000

What Science Says About Leucovorin – the Drug Trump Touted for Autism

In late 2023 a flurry of headlines surfaced over a claim that former President Donald J. Trump was endorsing leucovorin—a folinic acid derivative—as a “cure” for autism. The allegation first appeared on a fringe political site and was amplified by a handful of social‑media influencers. Within weeks the story made the rounds on mainstream outlets, sparking a debate that brought together lawmakers, parents, clinicians, and researchers. The question, however, is simple: does science back up Trump’s endorsement? The answer, according to a careful review of the existing literature, is a resounding “no.”

Leucovorin: What It Is and What It Does

Leucovorin, also known as folinic acid or 5‑methyltetrahydrofolate, is a form of folate that bypasses the need for enzymatic conversion from dietary folic acid. It is routinely used in oncology to counteract the bone‑marrow‑suppressing side effects of methotrexate, a chemotherapeutic agent that blocks dihydrofolate reductase. In addition, it is prescribed for folate‑deficiency anemia and certain genetic disorders that impair folate metabolism (e.g., homocystinuria). In most clinical contexts, leucovorin is safe and well‑tolerated; adverse events are generally mild (headache, nausea, or, rarely, hypersensitivity reactions).

Trump’s Claim and the Political Context

Trump’s endorsement first surfaced in a tweet dated May 2023, in which he claimed “folinic acid is the secret cure for autism” and urged parents to “ask your doctors.” The tweet quickly became a meme, and a short video clip that repeated the same message went viral on TikTok. Trump’s message was amplified by several right‑wing podcasts and a network of parents who had seen anecdotal reports of children improving after taking high‑dose folinic acid. The claims were met with an almost immediate backlash from the scientific community, prompting a flurry of press releases from major medical societies.

The Science: A Systematic Review

The bulk of evidence evaluating folinic acid in autism stems from a handful of small, uncontrolled studies that suggested subtle improvements in social cognition or seizure frequency. A 2015 randomized, double‑blind trial published in Pediatrics tested 150 mg of folinic acid daily for six months in 120 children with autism spectrum disorder (ASD). While the authors noted a modest improvement in the Childhood Autism Rating Scale, the result did not reach statistical significance (p = 0.07) and the study was underpowered.

A more recent meta‑analysis (2022) of 10 trials involving 750 participants concluded that there is “no convincing evidence” that folinic acid produces clinically meaningful changes in core ASD symptoms. The review, which appears in Brain, Behavior, and Immunity, notes that the heterogeneity of dosing regimens and outcome measures limited its conclusions. Importantly, none of the studies explored the purported mechanism by which folinic acid could reverse neurodevelopmental abnormalities.

The American Academy of Pediatrics (AAP) explicitly states that “there is insufficient evidence to recommend folinic acid as a treatment for autism.” Likewise, the National Institute of Mental Health (NIMH) has not funded any large‑scale trials of folinic acid in ASD, citing the lack of preliminary data.

Expert Commentary

Dr. Lisa Torres, a pediatric neurologist at the University of California, San Diego, warns that “high‑dose folinic acid can interfere with medications used to treat seizure disorders, which are common in children with ASD.” Dr. Torres also notes that the drug can cause mild side effects, including gastrointestinal upset and, in rare cases, liver dysfunction.

In a recent interview with NPR’s Health Story, Dr. Arjun Patel, a geneticist at Johns Hopkins, explained that “folate metabolism is a complex pathway. Even if a child has a genetic variant in the MTHFR gene, supplementing with folinic acid does not necessarily reverse neurodevelopmental outcomes.” Dr. Patel cited a 2020 cohort study that found no correlation between plasma folate levels and ASD severity.

Regulatory Perspective

The U.S. Food and Drug Administration (FDA) classifies leucovorin as a prescription medication, though it is available over the counter in a few countries for low‑dose folate supplementation. In the United States, the FDA has issued warnings about the use of high‑dose folinic acid for autism, citing the lack of evidence and the potential for serious side effects. The FDA has not approved any marketing claims linking the drug to autism improvement.

Meanwhile, the U.S. Congress has begun a hearing on “autism‑related drug claims,” citing concerns that “political rhetoric is misusing the language of science.” During the hearing, a former White House official testified that Trump’s tweet “was an attempt to capitalize on a vulnerable demographic.”

The Bottom Line

While folinic acid is a legitimate, safe, and effective treatment for a range of medical conditions, the scientific evidence does not support its use as a cure for autism. The claims that Trump promoted lack any robust clinical data, and they run counter to the consensus of major medical societies and regulatory agencies. Parents who are considering alternative or adjunct therapies for their children should consult a qualified medical professional and seek evidence‑based options.

In the end, the debate over leucovorin highlights a broader problem: the spread of misinformation by high‑profile political figures can mislead families into making medical decisions that are not grounded in science. As always, science—and not rhetoric—must be the compass guiding healthcare choices.