SupplementWell-studiedAntioxidant

NAC (N-Acetyl Cysteine)

Organ Support

Also known as NAC, NAC PCT, n-acetyl cysteine, N-Acetylcysteine (Liver)

Half-life

~6 hours

What is NAC (N-Acetyl Cysteine)?

Precursor to glutathione — the body's master antioxidant. Also a potent mucolytic.

How NAC (N-Acetyl Cysteine) works

Provides cysteine for glutathione (GSH) synthesis, directly replenishing the most depleted GSH limiter. Also directly reacts with reactive oxygen species. FDA-approved antidote for acetaminophen overdose — indicates potency of liver protection.

Benefits & uses

Boosts glutathione/antioxidant defense
Liver support
Respiratory/mucus support
May help mood/compulsive behaviors

Common uses: Liver support (on-cycle), glutathione replenishment, acetaminophen overdose, respiratory health.

LongevityRecovery

NAC (N-Acetyl Cysteine) dosage

Typical dose: 600–1800 mg/day in divided doses with food. On cycle: 600 mg twice daily. Separate from metal supplements (chelates zinc, copper).
Reference range: 600–1200 mg dailyClinical or reference range, not a personal recommendation.

NAC (N-Acetyl Cysteine) half-life

~6 hours (plasma NAC)

NAC (N-Acetyl Cysteine) side effects

Foul sulfur smell. GI upset. May blunt some training adaptations at very high doses.

Pronounced sulfurous odor
Nausea and GI upset — take with food
May blunt exercise-induced adaptations at very high doses (antioxidant dilemma)
Chelates minerals if taken simultaneously
Generally well tolerated
Mild GI upset
Sulfur smell

Warnings & monitoring

Support only — does NOT make oral steroids safe; bloodwork still required.

Monitoring: Liver enzymes (with bloodwork) if on hepatotoxic compounds.

NAC (N-Acetyl Cysteine) interactions

with Nitroglycerin
Avoid · severe
N-acetylcysteine potentiates the vasodilatory effect of nitroglycerin, causing severe hypotension and headache. This interaction is significant enough to contraindicate concurrent use without close medical supervision.
Timing: Do not use NAC while on nitroglycerin therapy
with Tudca
Compatible
NAC supports glutathione/liver detox while TUDCA addresses bile flow — non-overlapping hepatoprotective mechanisms.
Timing: Stack daily during oral AAS cycles

Track NAC (N-Acetyl Cysteine) in Protokol.

Log doses, model half-lives, check interactions, and line it all up against your bloodwork. Free on iPhone and Android.

Get it on Google Play

More Antioxidant