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

Conze D, Brenner C, Kruger CL · Scientific Reports

Dose-response for the biochemical target, measured against each participant's own baseline: whole-blood NAD+ was up 22 ± 9%, 51 ± 7% and 142 ± 14% at 100, 300 and 1,000 mg/day by day 14. At day 56 the two higher doses held (48 ± 8% and 139 ± 19%) and the lowest had faded to 10 ± 4%; the 100 mg arm was similar to placebo at every timepoint, so only 300 and 1,000 mg separated from it. Blood NAD+ fell significantly in the placebo group over the eight weeks. No flushing, no excess adverse events, no LDL elevation and no disruption of one-carbon metabolism.

Population

Overweight but otherwise healthy men and women

Intervention

Nicotinamide riboside 100, 300 or 1,000 mg/day for 8 weeks

Comparator

Placebo

Limitations

Designed to support an upper intake level, so the endpoints are safety and biochemistry rather than function. The headline percentages are changes from baseline, not differences from placebo, and the placebo group declined over the same period. Funded by the company that sells the product: two of the three authors are its employees and the third is its chief scientific adviser and the inventor of intellectual property it licenses.