Emerging Discussions on Folinic Acid and Acetaminophen in Autism.

PURPOSE: To provide a balanced update for clinicians and families on folinic acid (leucovorin) in autism and the evidence regarding prenatal acetaminophen (paracetamol) exposure.

METHODS

We summarise key randomised trials of folinic acid and the most methodologically rigorous observational evidence on prenatal acetaminophen, with attention to study design and subgroup findings.

RESULTS

Several small, randomised trials report short-term improvements in verbal or social communication with folinic acid. These effects appear stronger in biological subgroups, such as children with folate receptor autoantibodies (FRAA). However, the evidence remains limited due to small sample sizes, single-centre designs, and variable outcome measures. Notably, a randomised trial published in 2024 was retracted in January 2026, highlighting the need for caution regarding early findings. For acetaminophen, there is ongoing debate about its potential association with autism. A major Swedish cohort study using sibling control analysis (n = 2,480,797) found no association with autism, ADHD, or intellectual disability after adjusting for familial factors.

CONCLUSION

Clear, evidence-based communication is essential to help families navigate emerging evidence without being misled by premature claims.