NAD has gone from a relatively unknown term in biochemistry to one of the most talked-about topics in healthy aging. And there is a good reason for the interest. NAD is already at work in every cell in your body, helping turn nutrients into energy and supporting some of the cellular processes that keep us functioning over time.
So what exactly is NAD? Why has it become such a focus in aging research – and can we actually influence our NAD levels?
What is NAD?
NAD stands for nicotinamide adenine dinucleotide. It is a molecule found in every living cell.
The name is complicated. Its role is easier to understand.
NAD acts as a coenzyme – a molecule that other enzymes need in order to do their jobs. One of its most fundamental roles is helping our cells convert the food we eat into usable energy.
But NAD does more than support energy metabolism.
NAD+ is also required by enzymes involved in cellular signaling, stress responses and DNA repair. Among them are sirtuins – a group of enzymes that have become an important focus in aging research.
NAD is not a new “anti-aging molecule.” It is a fundamental part of normal human biology.
Why does NAD matter as we age?
Aging affects many of the systems that keep our cells functioning well – including energy metabolism, cellular repair and the way our bodies respond to stress.
NAD sits at the center of several of these processes.
That is why researchers have become increasingly interested in whether supporting NAD metabolism could help maintain normal cellular function as we get older.
Research in cells and animals has produced some striking results, and human research is now growing quickly. What is already clear is that NAD is biologically important and that the system can be influenced. What researchers are still working to understand is how changes in NAD translate into long-term health outcomes in people.
Can we increase NAD?
Yes.
The body can produce NAD+ from several different starting materials. Some of these are known as NAD precursors – molecules the body can use as building blocks to make NAD+.
Two of the best known are NR, nicotinamide riboside, and NMN, nicotinamide mononucleotide.
Both are part of the body’s NAD metabolism, but NR has been studied in several controlled human trials.
In one randomized, double-blind, placebo-controlled study, adults received 100, 300 or 1,000 mg of NR per day.
After just two weeks, NAD+ had increased by an average of:
100 mg NR → +22%
300 mg NR → +51%
1,000 mg NR → +142%
The increase was dose-dependent and remained elevated during supplementation.
This is one of the reasons NAD precursors have attracted so much attention: we are not simply talking about a theoretical mechanism. Human studies show that NAD metabolism can actually be changed.
Why is increasing NAD interesting?
Because NAD is not just sitting passively in our cells.
It is continuously being produced, used, broken down and recycled.
NAD+ is needed for normal energy metabolism. It is also consumed by enzymes such as sirtuins and PARPs, which are involved in processes including cellular stress responses, gene regulation and DNA repair.
The idea behind supporting NAD metabolism is therefore relatively simple:
If NAD is required for important cellular processes, maintaining its availability may help support the systems that depend on it.
That does not mean that raising NAD has been proven to slow human aging or extend lifespan. Those are much bigger questions, and clinical research is still developing.
But we do know two important things: NAD plays a central role in cell biology, and its metabolism can be influenced in humans.
NAD, NR and NMN – what’s the difference?
The names are often mixed together.
A simple way to think about them is:
NAD+ is the molecule our cells use.
NR and NMN are building blocks the body can use to produce NAD+.
Both NR and NMN are being studied in humans. At this point, there is not enough clinical evidence to say that one consistently produces better long-term health outcomes than the other.
For someone new to NAD, the most important distinction is simply this:
Taking an NAD precursor gives the body material it can use to produce more NAD+.
How quickly can NAD change?
Biologically, quite quickly.
In the clinical study above, increases in NAD+ were measurable within two weeks. Other controlled studies have also shown that NR can effectively stimulate NAD metabolism in middle-aged and older adults.
But a measurable change in NAD does not necessarily mean you will feel something immediately.
NAD is part of the machinery inside our cells – it is not a stimulant. Some people may report subjective changes over time, while others may not notice anything obvious at all.
The measurable effect is the change in NAD metabolism. How that feels can vary from person to person.
Is NR well studied?
NR has now been investigated in multiple human clinical trials.
In controlled studies it has generally been well tolerated at the doses and durations investigated, including studies involving middle-aged and older adults.
As with any supplement, individual circumstances matter. Anyone who is pregnant, breastfeeding, has a medical condition or uses medication should discuss supplementation with an appropriate healthcare professional.
How Lifeseeds approaches NAD
It was this broader understanding of NAD that shaped the development of Nexus.
Giving the body a precursor to produce more NAD is an important starting point. But NAD does not work in isolation.
It is continuously produced, consumed and recycled.
That is why Nexus was designed to do more than simply add another NAD precursor.
NR gives the body a building block it can use to produce NAD+. Human studies show that NR can significantly increase NAD+.
Luteolin was selected in part because of its relationship with CD38 – an enzyme that consumes NAD+. Laboratory research has shown that luteolin can inhibit human CD38 activity.
Pterostilbene has been studied for its relationship with sirtuins – NAD+-dependent enzymes involved in cellular metabolism, stress responses and repair-related processes.
Nexus also contains active forms of folate, vitamin B6 and vitamin B12, supporting normal metabolic processes including homocysteine metabolism.
Think of NAD like water in a bucket.
Adding more water is important. But it also makes sense to consider where that water is being used and where it may be lost.
That is the thinking behind Nexus:
Not simply more of one NAD precursor – but a formula developed around the NAD system as a whole.
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Scientific references
Migaud ME, Ziegler M, Baur JA. Regulation of and challenges in targeting NAD+ metabolism. Nature Reviews Molecular Cell Biology. 2024;25:822–840. Nature
Vinten KT, Trętowicz MM, Coskun E, van Weeghel M, Cantó C, Zapata-Pérez R, Janssens GE, Houtkooper RH. NAD+ precursor supplementation in human ageing: clinical evidence and challenges. Nature Metabolism. 2025;7:1974–1990. PubMed
Conze D, Brenner C, Kruger CL. Safety and Metabolism of Long-term Administration of NIAGEN (Nicotinamide Riboside Chloride) in a Randomized, Double-Blind, Placebo-controlled Clinical Trial of Healthy Overweight Adults. Scientific Reports. 2019;9:9772. doi.org
Martens CR, Denman BA, Mazzo MR, Armstrong ML, Reisdorph N, McQueen MB, Chonchol M, Seals DR. Chronic nicotinamide riboside supplementation is well-tolerated and elevates NAD+ in healthy middle-aged and older adults. Nature Communications. 2018;9:1286. doi.org
Kellenberger E, Kuhn I, Schuber F, Muller-Steffner H. Flavonoids as inhibitors of human CD38. Bioorganic & Medicinal Chemistry Letters. 2011;21(13):3939–3942. PubMed
Zhang L, Zheng J, Tie X, Lin T, Yang W, Li Z, Zou Y, Guan G, Liu P, Luo W, Li Z. Pterostilbene and its nicotinate derivative ameliorated vascular endothelial senescence and elicited endothelium-dependent relaxations via activation of sirtuin 1. Canadian Journal of Physiology and Pharmacology. 2021;99(9):900–909. PubMed
