N-Acetylcysteine

Uses

How it works

Benefits

Dosage & preparation

Risks & contraindications

Evidence quality

Highlighted claims

• NAC is the standard medical treatment for acetaminophen overdose in hospital settings. — The Most Common Cause of Liver Transplants
• NAC acts as the rate-limiting precursor for glutathione synthesis, directly replenishing the liver's depleted antioxidant defense. — The Most Common Cause of Liver Transplants
• NAC acts as a cysteine donor and glutathione precursor, replenishing the cellular antioxidant system under oxidative stress. — COVID-19: Treatment, Pathophysiology, and Clinical Management — Clinical Q&A
• NAC functions as an antioxidant by replenishing intracellular glutathione stores and directly scavenging reactive oxygen species via its sulfhydryl group. — COVID-19 ICU Treatment Protocols: Medications, Prone Positioning, and Emerging Evidence
• NAC is contraindicated in patients with a known allergy to acetylcysteine. — COVID-19 ICU Treatment Protocols: Medications, Prone Positioning, and Emerging Evidence
• A 1997 influenza trial found that NAC 600 mg twice daily did not reduce flu incidence but reduced cases severe enough to require staying home from approximately 75% to 25%, yielding an NNT of approximately 2. — COVID-19 ICU Treatment Protocols: Medications, Prone Positioning, and Emerging Evidence
• The standard NAC dose is 600 mg orally twice daily, available over the counter, and generally well-tolerated with heartburn as the primary reported side effect. — COVID-19 ICU Treatment Protocols: Medications, Prone Positioning, and Emerging Evidence
• A 1997 RCT found NAC 600 mg twice daily significantly reduced influenza symptom severity among infected participants but did not reduce infection rates. — COVID-19 ICU Treatment: Clinical Updates and Protocols
• A trial at Memorial Sloan Kettering is evaluating intravenous NAC 6 g/day as a continuous infusion targeting the coagulation mechanism in COVID-19. — COVID-19 ICU Treatment: Clinical Updates and Protocols
• Additional randomized controlled trial data would strengthen the evidence base for NAC as a cold and flu preventative. — N-Acetylcysteine for Preventing Colds and Flu