NAD+

NAD+ works as both a metabolic cofactor and a substrate for enzymes involved in energy metabolism, DNA repair, cellular signaling, and oxidative-stress responses. NAD+ levels can change with age and metabolic stress, which has led to extensive research into strategies for restoring or increasing cellular NAD+ availability. Research has largely focused on NAD+ precursors such as nicotinamide riboside (NR) and NMN, while direct NAD+ administration is increasingly being explored in IV and other clinical settings. A 2026 systematic review concluded that NAD+ augmentation clearly produces biological activity, but evidence for meaningful anti-aging or wellness outcomes in humans remains inconclusive.