N-Acetylcysteine (NAC) is a supplement derived from the amino acid L-cysteine and is known for its antioxidant properties. It is widely recognized for its ability to replenish intracellular levels of glutathione, a critical antioxidant that helps combat oxidative stress¹². As a result, NAC is often used to reduce the toxicity of acetaminophen overdoses and as a mucolytic to help clear mucus in lung conditions³¹.

NAC serves various roles:

1. Antioxidant and Anti-inflammatory: NAC acts as an antioxidant by increasing glutathione levels, which is crucial for maintaining cellular redox balance. It also has anti-inflammatory properties, suppressing tumor necrosis factor-alpha and interleukins by inhibiting nuclear factor kappa B²⁴.

2. Medical Uses: NAC is used medically to treat acetaminophen poisoning and is considered effective for this purpose³. It is also used for treating conditions such as lung collapse and to aid in diagnostic lung tests⁵.

3. Potential Health Benefits: Though NAC holds potential in treating other health conditions related to oxidative stress and inflammation, many of these uses still lack substantial clinical evidence¹⁵. Some studies suggest improvements in physical performance and antioxidant capacity through NAC supplementation⁶.

Overall, NAC is appreciated for its protective roles in antioxidant defense and managing inflammation, though further studies are needed to fully understand its efficacy in treating various health conditions⁶.

Footnotes

1. Micaely Cristina dos Santos Tenório, "N-Acetylcysteine (NAC): Impacts on Human Health," PubMed Central, 2021. ↩ ↩² ↩³

2. Špela Šalamon, "Medical and Dietary Uses of N-Acetylcysteine," PubMed Central, 2019. ↩ ↩²

3. MedlinePlus, "N-Acetyl Cysteine (NAC): MedlinePlus Supplements," MedlinePlus. ↩ ↩²

4. Diego Fernández-Lázaro, "Influence of N-Acetylcysteine Supplementation on Physical Performance and Laboratory Biomarkers in Adult Males," PubMed Central, 2025. ↩

5. Examine.com, N-Acetylcysteine (NAC): MedlinePlus Supplements. ↩ ↩²

6. Diego Fernández-Lázaro, "Influence of N-Acetylcysteine Supplementation on Physical Performance and Laboratory Biomarkers in Adult Males," PubMed Central, 2025. ↩ ↩²