NAD+ — The Coenzyme of Cellular Energy

Background

Nicotinamide Adenine Dinucleotide (NAD+) is a redox coenzyme present in every living cell. It is essential to ATP production via the electron transport chain, to DNA repair through the action of PARP enzymes, and to the activity of sirtuins (SIRT1–SIRT7), a family of NAD+-dependent deacetylases implicated in metabolic regulation and ageing biology.

What is proven

Tissue NAD+ concentrations decline with age in humans across multiple cell types — this has been replicated by independent laboratories using mass spectrometry. Causes include increased NAD+ consumption by CD38 in inflammatory tissue, reduced biosynthesis, and accumulation of senescent cells.

Precursor supplementation with nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN) reliably raises blood NAD+ levels in humans and improves mitochondrial function, insulin sensitivity, and exercise capacity in rodents. Multiple small human trials of NR and NMN report modest improvements in measures such as walking distance, blood pressure, and aerobic capacity.

What is NOT proven

Direct intravenous or subcutaneous NAD+ administration in humans has limited published pharmacokinetic data — NAD+ itself is a large, polar, charged molecule and how much enters cells intact versus being cleaved peripherally to nicotinamide and ADP-ribose remains debated.

Lifespan extension in humans has not been demonstrated for NAD+ or any of its precursors. Most commercial 'NAD drips' offered at wellness clinics are based on extrapolation from rodent and small human surrogate-endpoint data, not on randomised controlled outcome trials.

Open research questions

The relative efficacy of direct NAD+ versus precursor supplementation. Whether tissue-specific NAD+ restoration (brain, muscle, liver) is achievable with peripheral administration. Whether sirtuin activation by raised NAD+ produces clinically meaningful longevity or healthspan benefit in humans.

Regulatory status

NAD+ and its precursors NR and NMN are sold as dietary supplements in many jurisdictions. None are approved as therapeutic drugs for any anti-ageing indication. The FDA ruled in 2022 that NMN is no longer a permissible dietary supplement ingredient in the US following submission of an Investigational New Drug application by a pharmaceutical sponsor.

All Proteus® compounds are sold strictly for in-vitro research. Nothing on this page is medical advice, a treatment claim, or a recommendation for human use. Where compounds are licensed medicines in any jurisdiction, that approval applies to the licensed product supplied through a regulated pharmacy — not to research-grade material.