NADH stands for "nicotinamide adenine dinucleotide (NAD) + hydrogen (H)" and occurs naturally in the body, playing a role in generating energy. NAD supplements were created to help boost the amount of NAD+ circulating in the bloodstream, which may help slow down the health changes associated with aging. NAD+ is an essential coenzyme required by every living cell in the body to help generate energy. NAD supplements are made with precursors to NAD, which are substances that the body can transform into another form during a metabolic reaction. Some of the popularly researched precursors frequently used in supplements include nicotinamide riboside (NR), nicotinamide mononucleotide (NMN), and nicotinic acid (NA) .

People use NADH for chronic fatigue syndrome (CFS), high blood pressure, high cholesterol, athletic performance, depression, Parkinsons disease, and many other conditions, but there is no good scientific evidence to support these uses. However, human trials have shown that NAD+ supplementation may improve exercise performance in older adults, increase insulin sensitivity, and offer other health benefits.

NAD supplements may have side effects, and it is important to take them with caution. Taking NADH supplements might affect blood pressure and have other effects. NAD supplements are not regulated by the FDA, and it is important to consult a healthcare provider before taking them.