Hype, influencers and a billion-dollar market, but where is the actual evidence?
Over the past few years, NAD+ has become one of the longevity world's most talked-about supplements. Gwyneth Paltrow, Bryan Johnson, Andrew Huberman and countless influencers have promoted NAD drips and NAD boosters as almost self-evident for energy, recovery and "healthy aging".
The problem? The scientific evidence in humans is still very limited, and new research is now raising even more question marks.
A new study published in Nature Metabolism shows that blood levels of NAD+ do not appear to fall with age in healthy people, something that has long been one of the most central arguments behind the entire NAD industry.
The researchers analysed more than 300 individuals from several different datasets, including older people, elite athletes and frail individuals, without finding any clear age-related decline in NAD levels in the blood. The study did show that supplements can raise levels, but not that healthy people generally suffer from any "NAD deficiency".
This does not mean that NAD research is dead. On the contrary, there are still interesting questions around certain tissues, neurological diseases and rare metabolic conditions. But it does mean that much of the marketing has probably run far ahead of the data.
Perhaps the most interesting thing in the article is not the research result itself, but the comments from the researchers themselves. Matt Kaeberlein, one of the world's most well-known longevity researchers, says that the theory of universally falling NAD levels has almost become a "dogma" even though the evidence has been limited. He also describes how the field quickly moved from early laboratory research to aggressive marketing:
"As soon as it got into the supplement space, the need for data kind of went out the window, and it all became a marketing exercise."
Professor Riekelt Houtkooper, the researcher behind the new study, also admits that the field has been "incredibly hyped" over the past 15 years.
This is a recurring problem within the longevity industry. Early animal studies, promising mechanisms and biological plausibility are quickly turned into commercial products long before robust clinical evidence is in place.
It does not mean that NAD+ is "worthless". But today there is still very limited support for the idea that healthy people gain meaningful long-term health effects from expensive NAD drips or supplements. As Eric Topol recently wrote on X after the new research:
"The hype vastly exceeded the evidence."
It is an important reminder across the whole longevity field. Many interventions can sound scientific, advanced and future-oriented, but that does not automatically mean they improve health, lifespan or biological aging in humans.
Source: Nature Metabolism.
