NAC (N-Acetyl Cysteine) vs Phosphatidylserine

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

Major phospholipid component of neuronal cell membranes (15-20% of total phospholipid pool) that maintains membrane fluidity and supports signal transduction. Serves as a cofactor for protein kinase C (PKC), Na+/K+-ATPase, and other membrane-bound enzymes critical for neurotransmitter release. Blunts HPA axis hyperactivation by modulating corticotrophin-releasing factor (CRF) receptor interactions, attenuating cortisol release during physical and psychological stress. Facilitates acetylcholine, dopamine, and norepinephrine release, and enhances glucose metabolism in the brain.

Standard Dosing

100-300mg daily

Timing

With meals (fat-containing preferred for absorption). Can be taken morning or evening. Cortisol-blunting effects are relevant for evening/pre-bed dosing in stressed individuals.

Cycle Duration

Ongoing; no cycling required. Clinical benefits observed from 6-12 weeks.

Side Effects

• Mild GI upset at high doses
• Insomnia (if taken too late in some individuals)
• Rare: nausea
• GI distress (uncommon)
• Insomnia (at higher doses)
• Headache (rare)

Contraindications

• Soy allergy (if soy-derived — use sunflower-derived instead)
• Known soy allergy (soy-derived PS)
• Antiphospholipid syndrome (theoretical concern)

Best Stacking Partners