Research synthesisLow evidenceSmall effect5 studies · 2 beneficial · 3 neutral · 0 harmful
Across 5 studies on N-acetyl cysteine (NAC) for improved cognitive function, 2 reported beneficial effects (small to moderate), while 3 found neutral results. Most evidence comes from clinical populations (e.g., youth with NF1, mild cognitive impairment), with a median study duration of 126 days. The predominant effect size was small, and the most-studied dose range was approximately 2400 mg/day or 70 mg/kg/day in clinical populations.
- Effective dose range: ~2400 mg/day or ~70 mg/kg/day
- Studied populations: youth with neurofibromatosis type 1 (NF1), adults with possible vascular mild cognitive impairment, patients with Alzheimer's disease
Caveats: Many of the included studies did not reach statistical significance — effect may be smaller than the predominant direction suggests. Evidence base is small (only 5 studies) — conclusions should be considered preliminary. The two beneficial studies were low-evidence reviews, while the highest-quality RCTs (total n=540) showed neutral effects, highlighting a discrepancy between review-level signals and controlled trial findings.
Generated Jul 14, 2026