NMN (Nicotinamide Mononucleotide) vs Urolithin A

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)

Best Stacking Partners

Mechanism

Gut metabolite of ellagitannins that activates mitophagy — selective clearance of damaged mitochondria. Improves mitochondrial function, muscle endurance, and cellular energy production. Only ~40% of population can produce it endogenously.

Contraindications

• Limited long-term safety data beyond 4 months