NAC — Supplements
N-Acetyl Cysteine: glutathione precursor with mucolytic, hepatoprotective, and antioxidant properties.
Overview
N-Acetyl Cysteine (NAC) is the acetylated form of the amino acid L-cysteine and serves as the rate-limiting precursor for glutathione (GSH), the body's master endogenous antioxidant. NAC has FDA-approved indications as a mucolytic agent (Mucomyst) and as the standard-of-care antidote for acetaminophen overdose. Beyond these uses, NAC has been studied extensively for psychiatric conditions (OCD, addiction), respiratory health (COPD), liver protection, and as a broad antioxidant. It also modulates glutamatergic neurotransmission and reduces inflammatory cytokines.
Indications
- Glutathione repletion and antioxidant support
- Mucolytic therapy (respiratory conditions)
- Hepatoprotective support
- Psychiatric applications (OCD, addiction, compulsive behaviors)
- Acetaminophen toxicity prevention (adjunctive)
Mechanism of Action
NAC is deacetylated to L-cysteine, the rate-limiting substrate for glutathione synthesis
Dosing
| Compound | Dose | Frequency | Notes |
|---|---|---|---|
| NAC | 600 mg | 1-2 times daily | Take on empty stomach for better absorption; 1,200-2,400 mg/day for psychiatric indications |
Safety & Contraindications
- GI side effects (nausea, vomiting, diarrhea) are common, especially at higher doses
- Sulfurous taste and odor may reduce compliance
- Theoretical concern about reducing efficacy of certain chemotherapy agents (antioxidant interference)
- May cause bronchospasm in asthmatics (when inhaled)
- FDA briefly challenged NAC's status as a dietary supplement (2020-2022); now generally available