Intervention
N-Acetylcysteine (NAC)
Last updated 2026-07-02· Last reviewed 2026-07-02· 1 min read
Reviewed by the Ultimate Longevity Bible editorial team. Educational reference — not medical advice. See disclaimer.
Mechanism
- Provides cysteine for glutathione synthesis.
- Direct thiol antioxidant activity.
- Modulates NMDA-receptor and glutamate signalling in the CNS.
- Reduces disulphide bonds in mucus, hence mucolytic effect.
Evidence
- RCT-supported: paracetamol overdose (IV, in-hospital), COPD exacerbation reduction (moderate).
- Emerging: OCD (moderate), trichotillomania, cocaine and cannabis dependence (modest).
- Longevity: GlyNAC (glycine + NAC) is the specific formulation being studied in older adults; standalone NAC is common in longevity stacks but with thinner outcome data.
Practical considerations
- Standard oral doses 600–1,800 mg/day; higher for specific indications.
- Well-tolerated; occasional GI upset.
- Regulatory: banned from US supplement market by FDA briefly in 2020, reversed 2022.
- Alpha-Lipoic Acid — Intervention.
- Melatonin — Intervention.