What NAD+ is
Nicotinamide adenine dinucleotide (NAD+) is a coenzyme found in every living cell. It shuttles electrons in energy metabolism and is a required co-substrate for enzymes involved in DNA repair and stress responses (PARPs and sirtuins).
Why it matters for longevity
Tissue NAD+ levels decline with age in animals and humans, and low NAD+ is linked to mitochondrial and metabolic dysfunction. This has made raising NAD+ — typically with precursors such as nicotinamide riboside (NR) or nicotinamide mononucleotide (NMN), or via NAD+ infusions — one of the most marketed longevity interventions.
What the evidence shows
Oral NR and NMN reliably raise blood NAD+ markers in human trials, so target engagement is real. What is *not* yet established is a meaningful effect on ageing, healthspan or disease outcomes: most randomised trials are small, short and use surrogate endpoints. We therefore rate the longevity claim Emerging. Intravenous NAD+ in particular has little controlled outcome evidence and is not a proven anti-ageing treatment.
What to ask a clinic
Ask what outcome — beyond raising a lab value — is expected, the dose and infusion time (rapid IV infusion can cause discomfort), and how you will be monitored.