Glycine + NAC (GlyNAC) vs NR (Nicotinamide Riboside)

Mechanism

Combination that restores glutathione synthesis. Age-related glutathione deficiency is driven by glycine and cysteine precursor depletion, not enzyme dysfunction. GlyNAC corrects oxidative stress, mitochondrial dysfunction, inflammation, and insulin resistance in older adults.

Contraindications

• Active stomach ulcer (NAC)
• Asthma (NAC may cause bronchospasm in rare cases)

Mechanism

NR is converted to NMN by nicotinamide riboside kinases (NRK1/NRK2), then to NAD+ via the salvage pathway. Like NMN, elevated NAD+ activates sirtuins, PARPs, and CD38. NR has demonstrated ability to cross the blood-brain barrier and elevate brain NAD+ levels. It supports mitochondrial function, DNA repair, and circadian rhythm regulation through SIRT1-mediated deacetylation of BMAL1 and CLOCK proteins.

Standard Dosing

300-600mg daily

Timing

Morning with or without food.

Cycle Duration

ongoing

Side Effects

• Mild nausea
• Warmth/flushing (mild)
• GI upset
• Fatigue in some during initial days

Contraindications

• Active cancer (same theoretical NAD+ concern as NMN)
• Pregnancy/lactation
• Theoretical cancer concern shared with NMN

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