N-acetylcysteine (NAC)
Immune · Glutathione precursor / mucolytic
Tier B+
What this is
FDA sent warning letters to Amazon sellers in 2020 claiming NAC was a drug (not supplement) and unmarketable — triggered industry litigation. FDA subsequently issued 2022 final rule backing off enforcement, and NAC remains widely sold. Reasonable adjunct for respiratory issues and glutathione support. 'Detox' marketing exceeds evidence.
Mechanism
Cysteine prodrug; replenishes glutathione (rate-limited by cysteine availability); mucolytic via disulfide bond reduction; anti-inflammatory; FDA-approved for acetaminophen overdose and as mucolytic
Dose & route
600-1800 mg/day PO divided
Citations
- https://pubmed.ncbi.nlm.nih.gov/30653687/
- https://www.fda.gov/media/155675/download
- https://pmc.ncbi.nlm.nih.gov/articles/PMC8017281/
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This is an independent synthesis of published research by a non-clinician. Scores are opinions supported by citations, not prescriptions. See the full disclaimer and methodology for how this score was produced and what it does and doesn't mean.