MedChemExpress Nicotinamide riboside Chloride, an orally active NAD+ precursor, increases NAD+ levels and activates SIRT1 and SIRT3. Nicotinamide riboside Chloride is a source of vitamin B3 (niacin) and enhances oxidative metabolism, protection against high fat diet-induced metabolic abnormalities. Nicotinamide riboside Chloride reduces cognitive deterioration in a transgenic mouse model of Alzheimer’s disease.