NAD+: The molecule your body loses after 40 (and what you can do about it)

At age 60, your body has approximately 80% less NAD+ than when you were 20. This is no small detail: this molecule is behind how your mitochondria function, how your DNA is repaired, and how you age. The good news is that it is one of the few aging variables you can actually influence.

What is NAD+ and why the body cannot do without it

NAD+ (nicotinamide adenine dinucleotide) is a coenzyme present in all cells. You do not consume it directly: your body synthesizes it from precursors like tryptophan or vitamin B3. And it uses it continuously for critical processes:

• Mitochondrial energy production (ATP). Without NAD+, mitochondria cannot complete the respiratory chain. The direct result is functional fatigue, not the fatigue of having slept poorly.
• DNA repair. PARP enzymes, which repair breaks in the genome, consume NAD+ massively. A more damaged genome ages faster.
• Sirtuin activation. These proteins regulate gene expression, the response to oxidative stress, and inflammation. They need NAD+ to function. Without it, they are inactive even if they are present.

Why levels fall with age (and what accelerates them)

There are two self-reinforcing mechanisms:

Production decreases. The NAMPT enzyme, key in NAD+ synthesis, loses efficiency over the years. In addition, a sedentary lifestyle, chronic exposure to environmental toxins, and chronic sleep deficit deplete NAD+ faster than the body can replenish it.

Consumption increases. An enzyme called CD38—which is activated by systemic inflammation—actively degrades NAD+. The more low-grade inflammation, the more CD38, the less NAD+. It is exactly the opposite cycle to the one you want.

The result: an organism with fewer resources to repair itself, maintain mitochondrial function, and control inflammation.

NMN vs NR vs other precursors: what the evidence says

NAD+ cannot be supplemented directly (the molecule does not cross cell membranes well). Its precursors work:

NMN (nicotinamide mononucleotide): The most direct precursor. A trial published in Cell Metabolism (2022) with adults aged 45 to 60 found that 300 mg daily significantly raised blood NAD+ levels, with improvements in muscle function and insulin sensitivity. There are at least 7 clinical trials underway in 2024-2025.

NR (nicotinamide riboside): A slightly different route to NAD+. It has more human studies than NMN—including a 2023 meta-analysis that confirmed its efficacy in raising NAD+ consistently—and a very well-established safety profile. Less potent in direct comparisons, but more accumulated evidence.

Resveratrol: It is not a precursor, but it activates the sirtuins that NAD+ kicks into gear. Its combination with NMN or NR has a documented synergistic effect: more active sirtuins, more utilization of available NAD+. David Sinclair (Harvard) has been using it along with NMN in his personal protocol for over a decade.

CoQ10: Ubiquinone is essential for mitochondria to convert NAD+ into ATP. Without sufficient CoQ10, the available NAD+ results in less functional energy. Combining it with precursors enhances the result.

Signs that your NAD+ may be low

There is no standard blood test to measure intracellular NAD+ in conventional clinical practice. But there are associated functional signs:

• Fatigue that does not improve with proper rest
• Slow muscle recovery after moderate exercise
• Brain fog or difficulty maintaining sustained concentration
• Fragmented or non-restorative sleep
• Subjective feeling of accelerated aging in recent years

None are diagnostic on their own, but the combination of several, especially after 40, warrants attention.

What you can do: lifestyle first

Before supplementing, there are lifestyle levers with direct evidence regarding NAD+:

• High-intensity exercise (HIIT): Activates NAMPT and increases endogenous NAD+ production. Three 20-25 minute sessions per week produce measurable differences in 4-6 weeks.
• Intermittent fasting: Compressing your eating window to 10-12 hours activates sirtuins and reduces degradation by CD38.
• Sauna: The hormetic stress of heat activates NAD+ production as an adaptive response.
• Reduce alcohol: Its metabolism consumes NAD+ massively. It is one of the most direct and least discussed factors.

The role of supplementation

For those who already have the foundations in order—or want to accelerate results—NAD+ precursors offer a direct path. Lionzen Max combines NMN, Resveratrol, and CoQ10 in a formula designed for the mitochondrial and cellular longevity axis. It does not produce immediate results: it acts as a background lever, and changes are noticed in weeks, not days.

Evidence in humans is still under construction. What is solid: NAD+ levels fall with age, that deficit has documented functional consequences, and precursors raise those levels in a measurable way. The risk of supplementing with NMN or NR at the studied doses is minimal. The most useful question is not "does it work?", but "does it make sense to wait until you are 60 to start?"