All NAD+ precursors explained — NMN, NR, NA, NAM and more.
Not all NAD+ precursors are equal. Here is a complete guide to every major precursor, how they differ biochemically, and what the evidence says about each.
- NAD+ precursors differ in cost, evidence and conversion path — NMN and NR have the strongest human data.
- NMN ~500mg/day is the best-evidenced starting point for most NAD+ protocols.
- Niacin (NA) is cheap and effective but causes flushing; nicotinamide (NAM) inhibits sirtuins at high doses.
- Newer precursors (NAMN, NRH) show early promise but lack robust human data.
The most direct NAD+ precursor. Enters cells via dedicated transporters. Strong human clinical data. Expensive to produce, so quality varies enormously — always verify COA.
One step before NMN in the biosynthesis pathway. Well-studied, good safety profile, lower cost than NMN. Must be converted to NMN then NAD+ inside cells. Patented by ChromaDex (Tru Niagen).
The oldest NAD+ precursor, used clinically for decades for cholesterol. Highly effective at raising NAD+, very inexpensive. Major drawback: flushing at doses above 50–100mg. Slow-release forms mitigate this.
The amide form of niacin. No flushing. Raises NAD+ effectively. However, at high doses it inhibits sirtuins — counterproductive for longevity protocols. Best used at lower doses (250–500mg) combined with NMN.
A newer precursor entering via the Preiss-Handler pathway. Early research suggests it may avoid NAMPT bottlenecks that limit NMN efficacy. Limited human data so far. Watch this space.
A reduced form of NR that some studies show raises NAD+ more powerfully than NMN or NR in mice. Very new, limited human data. Not widely commercially available yet.
Which precursor should you use?
For most people starting a NAD+ protocol: NMN 500mg/day is the best starting point — strongest direct evidence, good tolerability, increasingly competitive pricing from verified EU suppliers. If cost is the primary concern, NR is a well-validated alternative at lower cost. Avoid high-dose NAM if sirtuins are a priority.