NMN (Nicotinamide Mononucleotide) vs NR (Nicotinamide Riboside)

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

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

Best Stacking Partners