NR vs NMN vs Niacin — Which Precursor?
Three precursors, three evidence bases
Nicotinamide Riboside (NR), Nicotinamide Mononucleotide (NMN), and plain old niacin (nicotinic acid) all raise NAD+ — but their absorption, cost, and human data differ substantially. The picture is messier than supplement marketing suggests.
NR — best human data
NR (branded Niagen) has the deepest human RCT evidence base among the commercial NAD+ precursors. Multiple trials (e.g. NIAGEN-CV) show dose-dependent NAD+ rises in blood. Clinical benefit data is more mixed — small improvements in blood pressure + arterial stiffness in some trials, not others.
NMN — popular but cloudier status
NMN is more popular in supplement form (partly on David Sinclair's platform). Initial human trials are promising. In 2022 the FDA ruled NMN is a drug, not a dietary supplement — removing it from US shelves. Enforcement has been inconsistent, and several brands remain available. The regulatory picture is unsettled.
Niacin — cheap, old, works
Nicotinic acid (vitamin B3) raises NAD+ effectively at 250–500 mg/day. Flushing is the main side effect, and sustained-release formulations blunt it. Niacin is the OG NAD+ booster: decades of clinical use, sub-$10/month cost. Advocates argue it delivers ~70% of the benefit of NR or NMN for ~10% of the cost.
Match the precursor to its reality
Connect each NAD+ precursor to its honest summary.
Key Takeaway
All three approaches raise NAD+ measurably. NR has the best human RCT data. Niacin is the cheapest proven option. NMN is in regulatory limbo. If budget is no object → NR. If you're cost-sensitive → niacin at 250 mg. If the goal is longevity signalling, the marginal difference between them is smaller than the supplement industry would have you believe.