Irritation Potential and Acute Efficacy of Topically Applied Niagen® (Niacinamide Riboside Chloride)

Human skin nicotinamide adenine dinucleotide (NAD+) levels decrease with age, likely contributing to the aging skin phenotype. It is hypothesized that topically applied NAD+ precursors, including niacinamide (nicotinamide) riboside (NR), may benefit skin aging. Three human clinical trials of topical Niagen®, NR chloride, were convened in healthy participants to evaluate its irritation potential; acute cosmetic NR alone and in formulation with Niagen NanoCloudTM sachet (NCS) did not result in significant irritation nor sensitization potential. Acute skin moisture content and skin barrier integrity significantly improved at ≥1.5% and ≥2.5% NR concentrations, respectively. Participant-reported outcomes included improvements to skin redness, moisture, and smoothness. These trials demonstrated that NR was nonirritating when applied topically, as a single ingredient product or when delivered in a dry, multi-ingredient product dissolved in a vehicle. As a single ingredient, NR significantly improved skin moisturization, skin smoothing, and skin barrier integrity, which may support the use of NR as a topical ingredient.