Nicotinamide Riboside
Nicotinamide Riboside (NR)
Also known as: NR, Niagen
A well-studied vitamin B3 form and NAD+ precursor that reliably raises NAD+ levels in humans, widely used in longevity supplement stacks.
Overview
Nicotinamide riboside is a form of vitamin B3 that the body converts into NAD+, the coenzyme central to energy metabolism and cellular repair. Human trials show it safely and reliably raises NAD+ levels, and it is one of the most studied NAD+ precursors, sold as a supplement (for example Niagen). Whether raising NAD+ translates into longer healthspan in humans is still being studied.
Mechanism of action
Converts to NAD+ through the salvage pathway, restoring NAD+ that declines with age and supporting mitochondrial and repair enzymes.
Key studies & citations
- Human2016
Nicotinamide riboside is uniquely and orally bioavailable in mice and humans
Oral NR raised blood NAD+ up to 2.7-fold in a human pilot and showed superior hepatic NAD+ kinetics in mice.
Nature Communications - Human2018
Chronic nicotinamide riboside supplementation is well-tolerated and elevates NAD+ in healthy middle-aged and older adults
Randomized crossover trial: 6 weeks of NR was well tolerated and effectively stimulated NAD+ metabolism.
Nature Communications - Human2019
Safety and metabolism of long-term administration of NIAGEN (nicotinamide riboside chloride) in a randomized, double-blind, placebo-controlled clinical trial of healthy overweight adults
8-week dose-ranging RCT supporting safety and dose-dependent NAD+ elevation.
Scientific Reports - Human2024
Nicotinamide riboside for peripheral artery disease: the NICE randomized clinical trial
90 patients: 6 months of NR improved 6-minute walk distance by 17.6 m versus placebo, a first functional outcome.
Nature Communications
Frequently asked questions
Is NR better than NMN?
Both raise NAD+. NR has more published human safety and NAD+ data and a clearer supplement status, while NMN's US regulatory status is contested. Longevity benefits for either are unproven.