What Is Leucovorin? FDA Approves Drug Label Update for Autism Treatment

The U.S. Food and Drug Administration (FDA) has approved a new label for leucovorin, a folate-based medicine, to recognize potential benefits for children with autism. The decision, announced Monday, follows years of small studies suggesting the drug may improve symptoms linked to cerebral folate deficiency in some patients.

Leucovorin, also known as folinic acid, is a modified form of vitamin B9. It is commonly used to reduce chemotherapy side effects, treat colorectal cancer in combination therapies, and address certain types of anemia. Now, for the first time, the FDA has allowed its use to be formally recognized in treating symptoms tied to autism spectrum disorder.

Leucovorin and Autism: What We Know

Leucovorin is designed to bypass barriers that prevent folate from reaching the brain. According to research cited by the FDA, some children with autism have antibodies that interfere with folate transport. Studies suggest up to 75 percent of children on the spectrum may be affected by this problem.

Clinical trials have shown promising results. In one study, 40 patients receiving leucovorin showed “substantial improvement” compared with those on a placebo. Improvements were most noticeable in receptive and expressive language skills. Dr. Richard E. Frye, a leading researcher, has reported that children who respond often show better communication and understanding of spoken words.

However, experts caution that leucovorin is not a cure. Dr. Alycia Halladay of the Autism Science Foundation noted that while some children improve significantly, others see no change. Larger placebo-controlled trials are still needed to confirm who benefits most and at what dose.

Impact, Risks, and Next Steps

The FDA’s move marks a milestone for autism treatment, giving families and doctors another tool. Still, experts warn that funding for autism research is limited, and priority may need to remain on other interventions.

Leucovorin is usually safe because it is based on a water-soluble vitamin, meaning most of it exits the body within 24 hours. Reported side effects include headaches, insomnia, agitation, and occasional aggressive behavior. The drug is available in pills, injections, and intravenous forms. Compounded liquid versions exist but may not be covered by insurance.

In summary, leucovorin is now officially recognized by the FDA as a treatment for cerebral folate deficiency linked to autism. While not a cure, it offers measurable improvements for some children, making it an important step in autism care research.

FYI (keeping you in the loop)-

Q1: What is leucovorin used for?

Leucovorin helps treat chemotherapy side effects, colorectal cancer, anemia, and now certain autism-related symptoms.

Q2: How does leucovorin help in autism?

It bypasses folate transport problems in the brain, improving communication and language in some children with autism.

Q3: Is leucovorin safe for children?

Yes, most side effects are mild, but some cases show agitation or headaches. Doctors should monitor use carefully.

Q4: Is leucovorin a cure for autism?

No, it is not a cure. It improves symptoms in some children, but results vary and more studies are needed.

Q5: Who can prescribe leucovorin for autism?

Doctors may now prescribe it under the updated FDA label, particularly for children with cerebral folate deficiency.

References

Reuters. (2025). FDA modifies leucovorin label for autism treatment.

Associated Press. (2025). Autism research highlights folate link.

BBC News. (2025). U.S. approves folate-based drug for autism symptoms.