Understand the source comparison
NAD+ Research: Comparison Across Precursor Types
NMN (Nicotinamide Mononucleotide) Requires conversion to NR before cellular uptake; some direct transport via Slc12a8 transporter 40–60% increase at 300–500mg daily Limited direct CNS penetration; relies on peripheral-to-central NAD+ synthesis No consistent co
No winner is assigned.
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- NMN (Nicotinamide Mononucleotide)
- Requires conversion to NR before cellular uptake; some direct transport via Slc12a8 transporter
- 40–60% increase at 300–500mg daily
- Limited direct CNS penetration; relies on peripheral-to-central NAD+ synthesis
- No consistent cognitive improvement in RCTs; cerebral blood flow improvement noted in one trial
- Best evidence for vascular effects; cognitive benefit unproven in humans
- NR (Nicotinamide Riboside)
- Direct cellular uptake via nucleoside transporters; no intermediate conversion required
- 30–50% increase at 500–1000mg daily
- Minimal direct BBB crossing; CNS NAD+ increase depends on salvage pathway activation
- Largest trial (n=108) showed no cognitive benefit despite NAD+ elevation
- Most studied precursor; reliable NAD+ increase but cognitive translation unclear
- NAD+ IV infusion
- 100% bioavailable in plasma; bypasses oral absorption
- Plasma levels spike 200–300% transiently
- Does not cross BBB; CNS effects require local synthesis from peripherally delivered precursors
- No published cognitive trials; anecdotal reports unreliable
- High plasma NAD+ does not equal brain NAD+; mechanism for cognitive effect absent
- Niacin (Nicotinic Acid)
- Converts to NAD+ via Preiss-Handler pathway; causes vasodilation (flushing)
- Modest increase; less efficient than NMN/NR
- Indirect CNS effects via peripheral vascular changes
- No RCTs measuring cognition; cardiovascular effects dominate
- Inferior to NMN/NR for NAD+ research; flushing limits tolerability