N-Acetyl Cysteine and Improved Attention Span

Doses used in studies

mg/day: 2,400 (median 2,400, IQR 2,400–2,400) — 1 study
mg/kg/day: 70 (median 70, IQR 70–70) — 1 study

Time to effect

Median: 4.2 months · IQR 3.5 months–4.9 months · Range 2.8 months–5.6 months — Reported in 2 of 2 studies

Safety in these studies

adverse eventsNo significant difference
N-acetylcysteine was generally well-tolerated, with adverse events comparable between groups.
from: Efficacy and safety of N-acetylcysteine in patients with mild cognitive impairment undergo
Overall tolerabilityReported
NAC was generally well tolerated, although two participants were withdrawn by parents because of worsening behavior.
from: A Randomized, Double-Blind, Pilot Study of N-Acetylcysteine for Motor and Cognitive Sympto
Overall tolerabilityReported
N-acetylcysteine was generally well-tolerated, with adverse events comparable between groups.
from: Efficacy and safety of N-acetylcysteine in patients with mild cognitive impairment undergo
behavior worseningReported
two participants were withdrawn by parents because of worsening behavior
from: A Randomized, Double-Blind, Pilot Study of N-Acetylcysteine for Motor and Cognitive Sympto

2 of 2 papers

A Randomized, Double-Blind, Pilot Study of N-Acetylcysteine for Motor and Cognitive Symptoms in Youth With Neurofibromatosis Type 1.
- 2026-07
- RCT · n = 481
- Pediatric neurology 180
- - Donald L Gilbert
  - Lindsey E Aschbacher-Smith
  - Karlee Y Migneault
  - David A Huddleston
  - Kim M Cecil
  - Dean W Beebe
  - Bin Zhang
  - Nancy Ratner
  - Carlos E Prada
- PubMed: 42173046
- DOI: 10.1016/j.pediatrneurol.2026.04.024
3 Insights on
- Improved Attention Span
- High evidence
- Large Human Trial
- Clinical
NAC did not improve any secondary or exploratory outcome at 8 weeks
Effect
Neutral
Effect size
Small
Significant
No
Dose
~70 mg/kg/day
Efficacy and safety of N-acetylcysteine in patients with mild cognitive impairment undergoing exercise-based cardiac rehabilitation program: a randomized controlled trial.
- 2026-04-27
- RCT · n = 59
- Alzheimer's research & therapy 18(1)
- - Damien Gallagher
  - Yejin Kang
  - Nathan Herrmann
  - Alex Kiss
  - Sandra E Black
  - Paul Oh
  - Susan Marzolini
  - Jennifer S Rabin
  - Ana Andreazza
  - Joel Ramirez
  - Fuqiang Gao
  - Mark Rapoport
  - Jinghan Jenny Chen
  - Kate Survilla
  - Danielle Vieira
  - Ethan Mah
  - Walter Swardfager
  - Krista L Lanctôt
- PubMed: 42045982
- DOI: 10.1186/s13195-026-02062-z
7 Insights on
- Improved Attention Span
- High evidence
- Clinical
with no significant differences between N-acetylcysteine and placebo (B=-0.04, 95% CI=-0.28 to 0.20, p=0.8) or in other cognitive domains.
Effect
Neutral
Effect size
Small
Significant
No
Dose
2400 mg/day

N-Acetyl Cysteine and Improved Attention Span

A Randomized, Double-Blind, Pilot Study of N-Acetylcysteine for Motor and Cognitive Symptoms in Youth With Neurofibromatosis Type 1.

Efficacy and safety of N-acetylcysteine in patients with mild cognitive impairment undergoing exercise-based cardiac rehabilitation program: a randomized controlled trial.