What Is NAD+ And What Are The Benefits? Explained Simply

Ever notice that energy feels different as you get older?

Not dramatically worse overnight. Just different. Recovery takes longer. Stress hits harder. You do all the “right” things, yet you do not bounce back the way you used to. This shift is part of normal ageing, and one of the molecules involved in that process is something called NAD+.

So, what is NAD+?

NAD+, short for nicotinamide adenine dinucleotide, is a coenzyme found in every single cell in your body. It plays a central role in cellular energy production and mitochondrial function, helping your cells generate usable energy. It also supports key repair processes that keep cells functioning properly over time.

As we age, NAD levels naturally decline. That age-related drop is one reason NAD+ supplements and NAD boosters have become a growing topic in conversations around energy and longevity.

To understand why it matters, we need to look at what NAD+ actually does inside the body.

Human research indicates that NAD+ concentrations may decline significantly with advancing age, with reductions observed across multiple tissues, including skeletal muscle, brain, liver, and plasma (Abdellatif et al., 2021; Freeberg et al., 2023; Conlon, 2022). This decline has led researchers to investigate NAD+ as a key molecule in ageing and metabolic resilience.

NAD+ helps your cells do two essential things, make energy and repair damage.

Every cell in your body needs fuel to function. Whether it’s your brain thinking, your muscles moving, or your heart beating, energy is required.

NAD+ supports the systems inside your cells that generate fuel so your body can perform everyday tasks efficiently.

It does not act like caffeine. You won’t “feel” NAD+ working. Instead, it supports cellular processes quietly, helping your cells do their job properly.

NAD+ plays a critical role in redox reactions that enable ATP production. Depletion of intracellular NAD+ has been shown to impair mitochondrial oxidative metabolism, particularly in high-energy tissues such as the heart (Abdellatif et al., 2021). This reinforces its importance in maintaining efficient cellular energy production.

Your cells experience stress every single day. From environmental exposure to natural wear and tear, small amounts of damage are constantly occurring.

NAD+ supports the internal systems that help repair and maintain your cells over time. As NAD levels decline with age, those repair processes may not function as efficiently.

This is one reason NAD+ is often linked to healthy ageing. It helps support the body’s natural maintenance systems.

NAD+ serves as a required co-substrate for enzyme families such as sirtuins and poly(ADP-ribose) polymerases, which regulate DNA repair, cellular stress responses, and longevity-related signaling pathways. Reduced NAD+ availability has been linked to impaired activity of these repair systems (Conlon, 2022; Abdellatif et al., 2021).

NAD levels naturally decrease with age, and by midlife may be significantly lower than they were in early adulthood.

Age is not the only factor.

Chronic stress, poor sleep, inflammation, and ongoing metabolic strain may all contribute to lower NAD levels. When your body is under constant pressure, it uses NAD+ to support repair and stress responses, which can accelerate NAD decline over time.

This combination of ageing and modern lifestyle demands is one reason interest in supporting NAD production has grown.

Age-related NAD+ decline has been documented in human tissues, with reported reductions ranging from approximately 10% to 80% depending on tissue type and population studied. Declines have been observed in skeletal muscle, brain, liver, plasma, and immune cells (Freeberg et al., 2023; Conlon, 2022). These reductions are thought to influence cellular resilience and metabolic function with age.

Because it is involved in foundational cellular processes, maintaining healthy levels may support:

• Cellular energy production

• Mitochondrial function

• Healthy ageing pathways

• Metabolic health

• Cellular repair mechanisms

It is important to keep expectations realistic. NAD+ is not a quick fix or instant energy solution. Its role is supportive, helping systems that influence how your body performs and adapts over the long term.

So if it is so important, the next logical question becomes, how do you support it?

Here is where many people get confused.

Most NAD tablets and capsules do not contain NAD+ directly. Instead, NAD+ supplements typically provide precursor compounds, ingredients your body can convert into NAD+.

Common examples include NMN, nicotinamide mononucleotide, and NR, nicotinamide riboside. These are often referred to as NAD boosters because they support the body’s natural NAD production pathways.

Once consumed, these compounds are absorbed and converted into nicotinamide adenine dinucleotide through internal biochemical processes. Rather than supplying NAD+ itself, supplements aim to help maintain healthy NAD levels by giving the body the building blocks it needs.

When choosing a nicotinamide adenine dinucleotide supplement, look for transparent dosing, quality sourcing, and third-party testing.

Human clinical trials investigating oral NAD+ precursors such as nicotinamide riboside and nicotinamide mononucleotide have demonstrated that supplementation can increase NAD+ and related metabolites in blood and other tissues. These compounds are generally considered safe and well tolerated in short- to medium-term studies. However, consistent improvements in clinical or physiological outcomes remain variable, and larger randomized controlled trials are still needed (Freeberg et al., 2023).

When you see recommendations for NAD dosage per day, they usually refer to precursor ingredients like NMN or NR rather than NAD+ itself.

Dosage varies depending on the specific ingredient and formulation, so it is important to follow product label guidance. Individual needs can differ based on age, health status, and overall lifestyle.

In general, NAD precursor supplements are considered well-tolerated. Some people may experience mild digestive discomfort when first introducing them. Certain niacin-based forms may cause temporary flushing.

As with any supplement, professional guidance is recommended if you have existing health conditions or are unsure about what is appropriate for you.

NAD+ is a naturally occurring molecule that plays a central role in cellular energy and repair. It helps your cells produce fuel and maintain their integrity as you age.

Because NAD levels decline over time, interest in supporting NAD production has grown. While sleep, nutrition, movement, and stress management remain foundational, NAD+ supplements may help support the body’s natural production pathways.

Understanding what NAD+ is, and how it works, gives you clearer insight into why it has become such a key part of the longevity conversation.

Abdellatif, M., Sedej, S., & Kroemer, G. (2021). NAD+ Metabolism in Cardiac Health, Aging, and Disease. Circulation, 144(22), 1795–1817. https://doi.org/10.1161/circulationaha.121.056589

Conlon, N. J. (2021). The Role of NAD+ in Regenerative Medicine. Plastic & Reconstructive Surgery, 150, 41S48S. https://doi.org/10.1097/prs.0000000000009673

Freeberg, K. A., Udovich, C. C., Martens, C. R., Seals, D. R., & Craighead, D. H. (2023). Dietary Supplementation With NAD+-Boosting Compounds in Humans: Current Knowledge and Future Directions. The Journals of Gerontology. Series A, Biological Sciences and Medical Sciences, 78(12), 2435–2448. https://doi.org/10.1093/gerona/glad106