NAD+

NAD+ — nicotinamide adenine dinucleotide — is a coenzyme found in every living cell and one of the most important molecules in metabolism. It is central to how cells turn nutrients into energy and to the enzymes that repair DNA and regulate aging. NAD+ levels fall with age, which is why restoring them is a major focus of longevity research.

What you’re reading about

NAD+ is usually studied alongside its precursors — the molecules the body uses to make it, chiefly NMN (nicotinamide mononucleotide) and NR (nicotinamide riboside). Much of the human evidence uses these precursors to raise NAD+ indirectly.

Mechanism under investigation

NAD+ fuels two enzyme families at the heart of aging research: the sirtuins, which regulate metabolism and cellular stress responses, and the PARPs, which repair DNA. It is also essential to mitochondrial energy production. Restoring NAD+ is hypothesized to support these systems as they decline with age.

Research applications

• Cellular energy and mitochondrial function.
• Metabolic and cardiovascular aging.
• DNA repair and cellular stress resistance.

Clinical outlook

NAD+ biology has moved firmly into human research through its precursors. Nicotinamide riboside has reached Phase 2 trials for arterial and cardiovascular health (NCT04040959), and NAD-augmentation approaches are in Phase 2 research for metabolic conditions such as diabetic kidney disease (NCT05759468). The central question researchers are chasing is where, and how much, raising NAD+ measurably benefits people — one of the liveliest debates in the science of aging.