13/02/2026
According to a randomized, double-blind, placebo-controlled trial published in Arthritis & Rheumatism, researchers evaluated N-acetylcysteine (NAC) in patients with systemic lupus erythematosus (SLE). Participants received either placebo or NAC at doses of 1.2 g/day or 2.4 g/day for three months. The 2,400 mg/day group showed the most significant improvement, with SLE Disease Activity Index (SLEDAI) scores dropping by nearly 40% compared to baseline, indicating a meaningful reduction in overall disease activity.
The study found that NAC works mechanistically by inhibiting mTOR activation in T cells, a pathway known to drive immune overactivation in lupus. By restoring intracellular glutathione levels and reducing oxidative stress, NAC suppressed abnormal immune signaling, improved regulatory T-cell function, and reduced autoantibody production. The benefits were observed within 12 weeks, with the higher dose producing the strongest clinical and immunological effects.
PMCID: PMC3411859 NIHMSID: NIHMS371296 PMID: 22549432