NAC (N-Acetyl Cysteine) vs Sulforaphane (from Broccoli Sprout Extract)

Mechanism

NAC is a precursor to L-cysteine, the rate-limiting substrate for glutathione (GSH) synthesis via glutamate-cysteine ligase. It directly replenishes intracellular GSH, the master endogenous antioxidant. NAC also modulates glutamatergic neurotransmission by stimulating the cystine-glutamate antiporter (system Xc-), influencing extrasynaptic glutamate levels. Additionally, it acts as a mucolytic by cleaving disulfide bonds in mucus glycoproteins.

Standard Dosing

600-1200mg daily

Timing

On empty stomach for best absorption, 30 min before meals. Split doses if >600mg.

Cycle Duration

Cycle 8 weeks on, 2 weeks off (to avoid potential downregulation of endogenous GSH production)

Side Effects

• Nausea
• GI upset
• Sulfurous odor/taste
• Rare: skin rash
• Potential zinc/copper chelation at very high doses

Contraindications

• Active gastric ulcers (may increase gastric acid)
• Asthma (rare bronchospasm with inhaled form)
• Concurrent chemotherapy (discuss with oncologist)

Best Stacking Partners

Mechanism

Isothiocyanate that activates Nrf2 — the master regulator of antioxidant defense. Upregulates glutathione synthesis, phase II detoxification enzymes, and heat shock proteins. Also inhibits HDAC (epigenetic modifier) and NF-kB (anti-inflammatory).

Contraindications

• Thyroid conditions (goitrogen at very high doses)
• Cruciferous vegetable allergy