NAC (N-Acetyl Cysteine)
The precursor your body needs to make its own master antioxidant, glutathione.
N-acetyl cysteine (NAC) supplies cysteine, the amino acid that limits how much glutathione, the body's central antioxidant, can be produced. It is widely researched for respiratory support and liver health, and in a medical setting, high-dose NAC is the standard hospital antidote for paracetamol overdose, a genuinely well-established use rather than a marketing claim. There is only one supplemental form in practical use. NAC's regulatory status has shifted in some countries over the years, so availability can vary by where you buy it.
Forms and bioavailability
Not all forms are absorbed equally. The form on your supplement label affects how much your body can actually use.
| Form | Absorption | With food | Timing | Evidence |
|---|---|---|---|---|
| N-acetyl cysteine | Typical | Either | Either | Likely |
Stack Almanac totals your NAC intake across every source you log, so a supplement and a combination formula that both include it don't quietly stack past what you intended.
Track your NAC (N-Acetyl Cysteine) in Stack Almanac
Last reviewed: 2026-07-08. Reference values are adult-general RDAs. Individual needs may vary. This page is for informational purposes only and is not a substitute for professional medical advice.