Compound · nac
T1Supplement

N-Acetyl Cysteine (NAC)

Acetylated form of L-cysteine that serves as the rate-limiting precursor for glutathione synthesis. Provides the cysteine residue needed by glutamate-cysteine ligase (GCL) to form gamma-glutamylcysteine, which is then conjugated with glycine to produce glutathione (GSH). Also functions as a direct free radical scavenger and mucolytic agent. Modulates glutamatergic neurotransmission through the cystine-glutamate antiporter, providing psychiatric applications.

Half-life
~6.25 hours
Bioavailability
~6-10% (oral)
Route
oral, intravenous
Evidence tier
T1 — Multiple RCTs
Optimization pillars
cellular-health · recovery
References
3 peer-reviewed
Dose ranges

Three tiers ordered by aggressiveness. Tier chips on every OPTIMIZE intervention let you filter the catalog by your evidence tolerance.

conservative
600 mg/day
General antioxidant and liver support
moderate
600 mg 2x/day
Standard hepatoprotective dose (1200mg total)
aggressive
600 mg 3x/day
High-dose protocol for oxidative stress (1800mg total)
Monitoring
  • alt
  • ast
  • ggt
  • bilirubin
  • homocysteine
Contraindications
  • active-bleeding-disorder
References
  • PMID:18990082N-Acetylcysteine: a review of clinical usefulness (an old drug with new tricks)J Adv Pharm Technol Res, 2011
  • PMID:25925411Oral N-acetyl cysteine reduces oxidative stress biomarkersFree Radic Res, 2015
  • PMID:16490323N-acetylcysteine as adjunctive treatment in bipolar depressionBiol Psychiatry, 2008
Notes

NAC is the glutathione precursor. Not glutathione itself — oral glutathione has abysmal bioavailability. NAC provides the cysteine that your body needs to build glutathione endogenously. This is the correct approach to glutathione repletion. The hepatoprotective data is so strong that NAC is the standard-of-care antidote for acetaminophen overdose in emergency departments. For enhancement contexts, it belongs in any liver support stack where hepatotoxic oral compounds are being used. The psychiatric data for OCD, addiction, and bipolar depression via glutamate modulation is a bonus mechanism that most supplement users are unaware of.

This is not medical advice

Discuss with a licensed clinician before starting, stopping, or changing any compound. This page documents what the research literature describes — it is not a prescription.

See N-Acetyl Cysteine (NAC) in a protocol matched to you

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