1. Anti-Aging Becomes a New Trend in Nutritional Supplementation
In the past, people’s choices for nutritional supplements were often limited to vitamins, minerals, proteins, and other categories, generally believing that these nutrients are closely related to maintaining the balance of human functions and strengthening the body. Today, the significance of dietary supplements is no longer limited to maintaining physiological functions, but also helps the human body delay aging, reduce disease risks, and thereby improve the quality of life.
2. NAD+ Leads Scientific Anti-Aging
Among them, NAD+ is a leader in anti-aging dietary supplements. As a small molecule naturally present in human cells, it controls hundreds of key enzymatic reactions, thereby regulating physiological processes such as mitochondrial function, redox balance, DNA repair, epigenetic stability, and autophagy. Moreover, studies have found that NAD+ levels show a declining trend with age. Although the declining trend of NAD+ with age differs between men and women, overall, the decline of NAD+ levels is closely related to the occurrence of aging and diseases. Restoring NAD+ levels by supplementing NAD+ precursors has shown potential in anti-aging and improving diseases in model animals. Preliminary human clinical studies have also proven the effect of oral NAD+ supplements (such as NMN, NADH, NR, etc.) in increasing NAD+, as well as the safety and tolerability of long-term use.
3. From Academic Craze to Universal Anti-Aging
Over the past 10 years, research on the anti-aging theme of NAD+ has set off an upsurge of pursuit in the academic community. According to Google Scholar statistics, more than 10,000 academic papers on NAD+ were included in 2023, accounting for about one-fifth of the total number of anti-aging papers in 2023—one out of every five anti-aging research articles discusses NAD+. The mechanisms of action related to NAD+ are constantly being revealed. The research not only wins by quantity but also by quality. Many studies have also been published in top journals such as Nature, Science, and Cell. Currently, the NAD+ anti-aging theory is supported by many top scientists. This wave of NAD+ anti-aging has finally blown from the scientific community to the public. NAD+ has become a popular anti-aging star molecule, and many anti-aging enthusiasts have included NAD+ supplementation in their daily supplement list.
4. Great Individual Differences in NAD+ Experience
Is supplementing NAD+ really useful? Many people who insist on taking NAD+ supplements often recommend NAD+ to others based on their own feelings—for example, NAD+ has helped them improve energy and work more focused, sleep more soundly with fewer night awakenings, have better exercise endurance and less shortness of breath when climbing mountains or stairs, or be less likely to catch a cold during the flu season. Although these personal feelings are indeed touching, it has to be said that people’s feelings about taking NAD+ are really very different, and personal feelings are difficult to scientifically quantify. So how do scientists judge whether taking NAD+ is effective?
The most common and intuitive method in scientific research is to detect NAD+ levels in whole blood after taking NAD+ supplements. Whole blood includes plasma and blood cells, so the NAD+ level in whole blood comes from both free NAD+ in plasma and NAD+ synthesized in cells after absorption by blood cells.
5. Scientific quantification of the time for NAD+ to take effect
So how long does it take for NAD+ levels to increase after taking NAD+ supplements? How long does it take for NAD+ levels to return to baseline after stopping NAD+ supplements? A study published in iScience in January 2026 revealed the answer. The research paper, titled "The NAD-brain pharmacokinetic study of NAD augmentation in blood and brain using oral precursor supplementation", was completed by a team led by Professor Christian Dölle from the Department of Neurology, Haukeland University Hospital, Norway.
In the pilot experiment of the study, a healthy male took 600mg of NR orally at 0 hours and 12 hours, respectively. And NAD+ levels in whole blood and brain were detected at 9 time points within 24 hours. It was found that NR supplementation did not bring changes in NAD+ levels within 24 hours, but an increase in NAD+-related metabolites could be observed.
After the pilot experiment, the researchers extended the taking time of NAD+ supplements, taking 1200mg of NR or NMN daily. After 2 weeks of continuous taking, NAD+ in the blood reached a steady state. After stopping taking, NAD+ slowly decreased, and NAD+ levels returned to near baseline after about two to three weeks. Both NMN and NR can significantly increase NAD+ levels in the blood, but NR seems to be better in terms of the increase range. More importantly, only 6 volunteers participated in the experiment, but obvious individual differences were observed. Some people could significantly increase NAD+ levels more than others after taking NMN or NR—for example, some people’s blood NAD+ levels may double after taking NAD+ precursors, and some even may triple.
In addition, after the subjects took NR orally for 4 consecutive weeks, the NAD+ level in their brains was detected to increase; while no significant change in NAD+ level in the brain was observed when taking NR or NMN for only 8 days. This result indicates that to have a significant impact on the NAD+ level in the brain, it is necessary to insist on long-term supplementation of NAD+ precursors.
6. Enlightenment from NAD+ Supplementation
This new study and related clinical studies bring us enlightenment:
Don’t be in a hurry to take NAD+ components for anti-aging; it takes at least 2 weeks to increase NAD+ levels to a steady state, and persistent taking after the steady state can keep NAD+ at a high level. After stopping taking, NAD+ levels will return to baseline in about 2 weeks, and the body feeling will gradually disappear. NAD+ is a natural component of cells, which has no strong stimulating effect on human functions, so there is no need to worry about dependence on NAD+ supplements. Long-term use of NAD+ supplements can bring the effect of increasing NAD+, but individual differences are great, and the body feeling feedback also varies from person to person.
References
Berven H, Svensen M, Eikeland H, et al. The NAD-brain pharmacokinetic study of NAD augmentation in blood and brain using oral precursor supplementation[J]. iScience, 2026.
