Glycine + NAC (GlyNAC) vs NMN (Nicotinamide Mononucleotide)

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

NMN is a direct biosynthetic precursor to NAD+ via the salvage pathway enzyme nicotinamide phosphoribosyltransferase (NAMPT). Elevated NAD+ activates sirtuins (SIRT1-7), PARP DNA repair enzymes, and CD38/CD157 signaling. SIRT1 activation deacetylates PGC-1alpha (mitochondrial biogenesis), FOXO transcription factors (stress resistance), and NF-kB (anti-inflammatory). NMN also enters cells via the Slc12a8 transporter, recently identified in the gut.

Standard Dosing

500-1000mg daily

Timing

Morning on empty stomach. Sublingual absorption bypasses first-pass metabolism.

Cycle Duration

ongoing

Side Effects

• Mild GI discomfort
• Flushing (rare, unlike niacin)
• Mild headache during initial use

Contraindications

• Active cancer (theoretical concern: NAD+ may fuel rapidly dividing cells)
• Pregnancy/lactation (insufficient data)
• Theoretical concern in active cancer (NAD+ fuels all rapidly dividing cells)

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