Metabolic aging is the imbalance or dysregulation of our metabolism as a function of aging. As we age, levels of NAD+ decline dramatically. NAD+ is a key metabolite whose levels are closely monitored by the cell in order to tune and balance its metabolic reactions. Regulating the vast number of metabolic reactions to maintain balance or homeostasis between energy production and usage is critical for cell health. In addition to the decline in NAD+ level, the activity and levels of sirtuins (NAD-dependent enzymes involved in regulating metabolism and maintaining energy homeostasis) also decline. The ingredients in Signal are designed to work synergistically to promote metabolic balance and health by elevating NAD+ levels and activating sirtuin 3.