N-acetyl cysteine (NAC) is a semi-synthetic derivative of the naturally occurring amino acid L-cysteine.

developed as a mucolytic drug in the 1960s for cystic fibrosis and COPD.

NAC is a cysteine prodrug and glutathione precursor that helps scavenge free radicals and bind metal ions into complexes. Along with glutamine and glycine, it helps make and replenish glutathione. You can take NAC to help boost glutathione levels in your body.

NAC is often more effective than supplementing glutathione directly.

oral glutathione is poorly absorbed and largely broken down before reaching cells, while NAC delivers cysteine intracellularly where it's used to manufacture fresh glutathione on-site.

NAC could block excessive production of angiotensin II which cannot be cleaved to angiotensin 1-7 by ACE2. this may decrease pulmonary disease severity.

since NAC also breaks the viral disulfide bonds required for host cell invasion, it may help prevent direct SARS-CoV-2 invasion into cells.

proposed dosage: 600 mg twice daily for prevention, 1200 mg twice daily upon first onset of symptoms.

the gold-standard treatment for acetaminophen (Tylenol) overdose worldwide.

NAC improves sperm motility, morphology, and DNA fragmentation through oxidative stress reduction in testicular tissue.
for female fertility: NAC is comparable to metformin for improving ovulation, insulin sensitivity, and hormone balance in PCOS.

NAC was widely researched as anticancer agent for reducing cancer hostility, increasing apoptosis of cancer cells, and reducing catabolism, mitochondrial dysfunction, inflammatory mediators, and oxidative stress.

NAC disrupts the metabolic symbiosis between stromal and carcinoma cells — blocking the lactate shuttle that feeds cancer cell mitochondria. it also reduces cancer cell invasion and metastasis through matrix metalloproteinase (MMP) inhibition. paradoxically, some cancer types may upregulate glutathione as a resistance mechanism — in those cases NAC could theoretically support cancer resistance to oxidative stress from chemotherapy, making the cancer-NAC relationship context-dependent and requiring professional guidance.

used in protection against contrast-induced nephropathy and thrombosis. before contrast dye imaging for patients with compromised kidney function — NAC pretreatment prevents the acute kidney injury that iodinated contrast agents can cause through oxidative damage.

used as antioxidant in protection against thrombosis. NAC reduces platelet aggregation through thiol-mediated disruption of platelet activation, reduces endothelial oxidative stress, and breaks down fibrin networks through disulfide bond cleavage. the anticoagulant mechanism — direct dissolution of fibrin cross-links — is particularly relevant to the white fibrous clot concerns associated with COVID-19 spike protein pathology.

studies have shown no maternal or fetal harmful effects of NAC treatment. generally excellent safety profile.

reduces efficacy of some antibiotics when taken simultaneously — separate dosing by 2 hours.

It helps break down mucus in your body. Some people take NAC as a supplement to help treat respiratory problems, heart issues, or other conditions.