Using N-acetylcysteine to address repetitive behaviors in children with autism

Targeting the Neurobiology of Restricted and Repetitive Behaviors in Children With Autism Using N-acetylcysteine: a Single-dose Challenge Study

Phase 2 Interventional Stanford University · NCT04278898

This study is testing if a nutritional supplement called N-acetylcysteine can help reduce repetitive behaviors in children with autism aged 3 to 12.

Quick facts

PhasePhase 2
Study typeInterventional
Enrollment24 (estimated)
Ages3 Years to 12 Years
SexAll
SponsorStanford University Academic / other
Locations1 site (Stanford, California)
Trial IDNCT04278898 on ClinicalTrials.gov

What this trial studies

This study aims to investigate the effects of N-acetylcysteine (NAC), a nutritional supplement, on restricted and repetitive behaviors in children diagnosed with Autism Spectrum Disorder (ASD). Participants aged 3 to 12 years will receive a single dose of NAC, and the study will utilize magnetic resonance imaging and electroencephalography to explore the neurobiological mechanisms behind any observed changes in behavior. The research seeks to build on previous small-scale trials that suggested NAC may reduce symptom severity in ASD. The findings could provide insights into the clinical benefits of NAC and its potential role in treating ASD symptoms.

Who should consider this trial

Good fit: Ideal candidates are children aged 3 to 12 years with a confirmed diagnosis of Autism Spectrum Disorder and moderate to severe restricted and repetitive behaviors.

Not a fit: Patients with known genetic abnormalities associated with Autism Spectrum Disorder or severe psychiatric disorders may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could offer a new, well-tolerated treatment option for reducing repetitive behaviors in children with autism.

How similar studies have performed: Previous small-scale trials have shown promise for NAC in reducing symptoms of autism, indicating potential for success in this approach.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* children between 3 years and 12 years 11 months at the time of consent
* diagnosis of Autism Spectrum Disorder confirmed with the Autism Diagnostic Interview-Revised (ADI-R) and the Autism Diagnostic Observation Schedule-2 (ADOS-2), or Brief Observation of Symptoms of Autism (BOSA), or Childhood Autism Rating Scale- Second Edition (CARS-2).
* at least moderate Restricted and Repetitive Behaviors severity defined by a Children's Yale-Brown Obsessive Compulsive Scale for children with autism spectrum disorder score ≥ 11,
* physical development indicative of prepubescence as defined by the criteria for Tanner Stage 1,
* medically stable,
* passes MR safety screening (e.g., no metal in the body).

Exclusion Criteria:

* presence of known genetic abnormalities associated with Autism Spectrum Disorder (e.g. Fragile X),
* current or life-time diagnosis of severe psychiatric disorder (e.g., schizophrenia),
* presence of significant medical problems that would interfere with participation,
* the inability of at least one caregiver to speak/read English to a sufficient level to complete study requirements and materials,
* individuals taking antioxidant agents and glutathione prodrugs, or
* the inability/unwillingness to swallow an agent during the screening visit.

Where this trial is running

Stanford, California

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Autism Spectrum DisorderMagnetic Resonance ImagingN-acetylcysteineRestricted and Repetitive Behaviorselectroencephalography
Last reviewed 2026-06-10 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.