Does NAD+ supplementation slow biological aging?

NAD+ is a molecule that plays a central role in your cells' energy supply and in the repair of DNA damage. Both animal research and a limited number of human studies consistently show that NAD+ levels decline as you age. How pronounced that decline actually is in humans remains unclear, because tissue data are scarce^1,2,3,4.

What clinical studies do clearly show is that NAD+ supplements, such as NMN or NR, reliably raise NAD+ levels in blood and tissues. That effect has been confirmed in humans on multiple occasions^3,5,4. The supplements also appear to be safe and well tolerated; no serious side effects have been reported to date^3,5.

The real question, whether higher NAD+ levels produce any tangible benefit, has not yet been answered. Studies examining muscle strength, memory and heart function yield mixed results. The groups are small, doses vary and study duration is short. Firm conclusions about functional gains in humans cannot therefore be drawn^3,5,4.

In mouse studies the findings are more positive. In mice with an Alzheimer-like condition, NR supplementation reduced brain inflammation, DNA damage and cellular ageing, and improved memory and the functioning of brain cells⁶. Other mouse studies show that raising NAD+ improves various forms of heart disease and extends healthy lifespan⁷. However, mouse results do not always translate to humans.

Whether NAD+ supplements genuinely slow biological ageing or extend healthy lifespan in humans has not been demonstrated at this point. Large, long-term studies are lacking, and the existing human data are too limited to confirm the promising animal results^4,3,5,2. If you still want to try NMN or NR, the supplements demonstrably raise your NAD+ levels and appear to be safe, but whether that has any meaningful effect on ageing remains an open question for now.