NMN (nicotinamide mononucleotide) is a precursor to NAD+ (nicotinamide adenine dinucleotide) and plays a crucial role in cellular metabolism and energy production. Supplementing with NMN is an effective way to restore NAD+ levels that decline with age. In skincare products, NMN can increase intracellular NAD+ levels, protecting skin cells from damage caused by ultraviolet (UV) radiation and reactive oxygen species (ROS). It also helps to eliminate ROS by reducing oxidative stress and inflammation through decreased NF-κB activity and reductions in cytokines such as TNF-α and IL-1/6. This ultimately protects cells from inflammation and apoptosis.