NAD+: a molecule with a market ahead of its evidence

Nicotinamide adenine dinucleotide is not a fringe molecule. It is a coenzyme sitting at the centre of cellular energy metabolism and a substrate for enzymes involved in DNA repair and cellular signalling. Tissue levels decline with age in several species, and restoring them in short lived animals produces effects that are easy to describe and hard to ignore. That is a legitimate research programme, and it is also the entire foundation of a large commercial market in intravenous NAD+ administration.

There is no marketing authorisation anywhere in the European Union for NAD+ given intravenously for ageing, fatigue, cognition, addiction or recovery. Human data consist mostly of small, short studies, many of them of oral precursors rather than the infused molecule, with biochemical endpoints such as blood NAD+ metabolite levels. Those trials are designed to show that a compound raises a measurement. They are not powered, and mostly not designed, to detect changes in how long people live, how well they think or whether any disease course is altered.

The gap between mechanistic plausibility and demonstrated clinical benefit is the whole story. A pathway can be real, central and elegantly mapped while intervention in it does nothing useful in a person, and the history of ageing biology is largely a history of that disappointment. What the evidence does not support is any claim that raising NAD+ slows human ageing, restores energy, improves cognition or treats any condition.

There is a further constraint that shapes what you see publicly. In several jurisdictions an unauthorised medicinal product may not lawfully be advertised to the public at all, whatever the state of the science. That is one reason serious practitioners have gone quiet about it while the loudest marketing continues elsewhere, and why silence in this field is a poor guide to what is actually being done.