NAD+

NAD+ is a natural coenzyme that cells need to make energy and carry out many basic jobs. It helps cells turn food into usable energy and also takes part in DNA repair, stress response, and cell signaling. Researchers study NAD+ because its levels and use can change with age, metabolic stress, inflammation, and problems with mitochondria. NAD+ is also connected to enzymes such as sirtuins and PARPs, which are studied in aging and cell-repair research. This makes NAD+ much more than an "energy" topic. It sits near the center of how cells manage fuel, repair damage, and respond to stress.