What is NAD+ and its Function in the Body?

NAD+ is a universal coenzyme present in all living cells. It’s a signaling molecule that tells cells when to conserve resources, defend against threats, or activate longevity pathways. Our bodies depend on NAD+ for energy production, DNA repair and countless other processes. 

What started as a simple scientific observation over 100 years ago has evolved into one of the most important metabolites we know for keeping cells healthy and functioning.

In this deep dive, we cover everything you need to know about the cellular guardian known as nicotinamide adenine dinucleotide.

Why Does Your Body Need NAD+?

Your body needs NAD+ for a wide range of biological activities that include powering your cells, protecting your DNA, and regulating your genes.

At its most basic level, NAD+ helps convert the carbohydrates, fats, and proteins from your diet into cellular energy through a complex series of metabolic reactions in your mitochondria¹—often referred to as the “powerhouses” of the cell.

But energy production is just the beginning of NAD+’s critical functions. It’s an essential cofactor for sirtuins, a family of proteins that regulate gene expression, metabolism, and cellular stress responses.

When your DNA gets damaged from everyday stresses like UV radiation or environmental toxins, NAD+ supports repair enzymes called PARPs (poly ADP-ribose polymerases) that help maintain genomic stability². Without enough NAD+, these repair mechanisms can’t function properly and this leads to cellular damage over time.

Your circadian rhythm, the body’s internal clock that governs sleep, hormone production, and metabolism, relies heavily on NAD+³. Levels of this molecule naturally fluctuate throughout the day, helping to synchronize various biological processes with your daily cycle. 

NAD+ is also important for maintaining your body’s metabolic flexibility, the ability to switch between using carbohydrates and fats for fuel⁴. This is crucial for managing blood sugar levels, supporting exercise performance, and maintaining a healthy body weight. 

“NAD+ is the closest we’ve gotten to a fountain of youth. It’s one of the most important molecules for life to exist”
– Dr. David Sinclair, Professor of Genetics at Harvard Medical School
Source: TIME interview (2018)

The Origin Story of NAD+

The story of NAD+ begins like many great scientific discoveries – with curious researchers and unexpected findings.

In 1906, scientists Arthur Harden and William John Young were studying how yeast makes alcohol when they noticed something peculiar: a mysterious heat-resistant molecule that supercharged fermentation. 

This molecule would later be identified as NAD+. By the 1930s, scientists Hans von Euler-Chelpin and Otto Warburg had begun unraveling its structure and function, revealing NAD+’s role in cellular energy production.

The next major breakthrough came when researchers Jack Preiss and Philip Handler mapped how the body creates NAD+ from vitamin B3. Their work explained why niacin deficiency caused pellagra, a disease that had puzzled doctors for centuries.

But the most exciting chapter in NAD+’s story opened in 2000, when researchers in Leonard Guarente’s lab made a new discovery: NAD+ wasn’t just an energy molecule – it was a central player in longevity through its interaction with sirtuins.

This finding shifted NAD+ from a supporting character to a starring role in aging research. Today, as we grapple with questions about healthy aging, that century-old discovery continues to unlock new possibilities in the study of cellular health.

How NAD+ Works Inside Your Cells

NAD+ works by a precise chemical process of accepting and donating electrons. Inside your cells it exists in two main forms: NAD+ (oxidized) and NADH (reduced), switching between them as it generates energy.

This electron transfer process is crucial in the mitochondria’s electron transport chain. Here, NADH delivers its electrons to special protein complexes, triggering a chain reaction that produces ATP. This molecular process explains why NAD+ is needed to turn nutrients into usable cellular energy.

Beyond this primary function, NAD+’s molecular structure makes it a perfect “sensor” for cellular health. When NAD+ binds to sirtuins, it changes the shape of these proteins, which then activates them. This structural change allows sirtuins to “talk” to their target proteins, initiate cellular repair and gene regulation.

The cellular demand for NAD+ follows a hierarchy. When DNA damage occurs, PARP enzymes quickly consume available NAD+ for repair work, leaving less for energy production and other functions.

This prioritization system is why NAD+ depletion can have widespread effects on cellular health – when levels are low, cells have to choose between functions and compromise performance across multiple systems.

The Link Between NAD+ and Aging

NAD+ levels drop by about 50% by middle age. A protein called CD38 becomes more active with age, using up more NAD+, and a protein (NAMPT) that helps make NAD+ becomes less efficient⁵. This decline is associated with hallmarks of aging: mitochondrial dysfunction, oxidative stress and cellular senescence⁶.

Studies on mice have shown that boosting NAD+ can reverse some signs of aging – improve energy metabolism, make muscles work better and increase lifespan. Scientists have found that people who don’t have enough NAD+ can develop serious health problems, including brain disorders, heart disease, and insulin resistance⁷.

When NAD+ levels fall with age, sirtuins can’t effectively regulate key proteins involved in stress response and energy production. SIRT1, one of our key sirtuins, loses its ability to keep our body’s internal clock ticking smoothly, which impacts sleep quality and metabolic health.

Meanwhile, when PARPs spring into action to fix DNA damage, their repair work drains even more NAD+⁸. It’s a bit like firefighters using up the city’s water supply while trying to put out spreading flames – the process of fixing one problem creates another.

Can You Boost NAD+ Naturally?

Your body’s NAD+ levels can be supported through several natural approaches.

Exercise, particularly high-intensity interval training (HIIT), stimulates NAMPT⁹, your body’s key NAD+-producing enzyme. Fasting or calorie restriction also triggers NAD+ production – even time-restricted eating, where you consume food within an 8-10 hour window, can help.

Your diet matters too. Foods rich in NAD+ precursors include grass-fed beef, fish, mushrooms, green vegetables, and fermented foods. Some B-vitamin rich foods, especially those containing niacin (B3), directly support NAD+ production.

Getting quality sleep and managing stress helps preserve your NAD+ stores, as chronic stress and poor sleep can deplete NAD+. Heat exposure through saunas may also boost NAD+ levels by activating cellular stress response pathways¹⁰.

By middle age, even the healthiest lifestyle may not be enough to fully counteract low levels of NAD. That’s why researchers are still studying additional ways to support cellular NAD+ levels as we age.

Supplementation and Therapies: Do They Really Work?

Your body has a system to turn certain molecules into NAD+. Think of it like having the right key for a lock – some compounds fit perfectly, others can’t get in the door. This is why not all NAD+ boosters work equally well.

Scientists have zeroed in on two effective compounds: NMN and NR, short for nicotinamide mononucleotide and nicotinamide riboside.

These small molecules are direct precursors to NAD+ that work through your body’s natural pathways. Recent studies paint an impressive picture of how well they work.

Our intestines have a special transporter encoded by the Slc12a8 gene that helps NMN get into our cells.¹¹ A clinical trial published in Frontiers in Nutrition backs this up – healthy volunteers taking NMN for 12 weeks showed significant increases in their blood NAD+ levels compared to placebo, with no concerning side effects¹².

NR appears to be equally effective. Studies in humans show that NR can boost blood NAD+ levels up to 2.7 times after just one dose¹³. NR was more effective than nicotinic acid in this regard. Research has also shown that NR can boost NAD+ in the brain after a short period of supplementation¹⁴.

What about the NAD+ IV therapy trend? Despite popularity in wellness clinics, it faces a basic biological challenge. The NAD+ molecule itself is too large to easily enter cells, making it less effective than its smaller precursor compounds.

The science is pretty clear that oral supplementation with NMN or NR is the most practical evidence-backed approach to raising NAD+. These molecules work in harmony with your body’s natural processes, supporting rather than forcing cellular NAD+ production.

This understanding of NAD+ biology is what guided the development of Jinfiniti’s Vitality ↑® NAD+ Booster Powder.

Beyond pure NMN, this formula includes synergistic compounds like D-ribose and creatine monohydrate that support your body’s energy production systems. Niacinamide provides an additional NAD+ precursor, optimizing your cellular NAD+ levels through multiple pathways. 

But what really sets this apart is the ability to measure your results. With our Intracellular NAD® Test, you can track your actual cellular NAD+ levels and adjust your supplementation based on real data rather than guesswork.

The Debate Around NAD+: Hype or Hope?

Scientists rarely agree on everything, but the buzz around NAD+ has sparked particularly lively debates in research circles. While some herald it as a key to healthier aging, others urge caution about overstated claims.

The evidence supporting NAD+’s fundamental role in cellular health stands on solid ground. Hundreds of peer-reviewed studies confirm its essential functions in energy production, DNA repair, and cellular stress response. However, researchers emphasize that results vary among individuals, and more long-term studies are needed.

While we know NAD+ levels decline with age, scientists still question whether this drop directly causes aging or simply accompanies it. It’s the classic chicken-or-egg puzzle of biology.

For those following the science, NAD+ represents genuine hope grounded in real biology. The key lies in maintaining reasonable expectations while appreciating the complexity of how our cells age and function.

Frequently Asked Questions About NAD+

What happens when NAD+ is too high?

Excessive NAD+ levels can trigger increased inflammation and oxidative stress in some cases. Your body typically maintains tight control over NAD+ levels, but supplementing beyond what your cells can effectively use may lead to imbalanced energy metabolism and cellular stress responses.

Can you take too much NAD+?

While NAD+ precursor supplements are generally well-tolerated, excessive doses may cause mild side effects like flushing, headaches, or gastrointestinal discomfort. The key is finding your optimal dose through testing and gradual adjustment rather than assuming more is better.

How long does it take to see results from NAD+ supplementation?

Results vary by individual. Some report increased energy and mental clarity within 2-4 weeks, while other benefits like improved sleep quality may take 8-12 weeks. Regular NAD+ testing provides the most reliable way to track your progress, as subjective feelings don’t always reflect cellular changes.

Does taking NAD+ precursors affect sleep or circadian rhythm?

Studies show that healthy NAD+ levels can improve sleep quality by supporting your body’s circadian rhythms. Morning supplementation typically works best as it aligns with your body’s natural NAD+ production cycle. For optimal results, take your supplements before noon to support your natural sleep-wake patterns.

How do common medications interact with NAD+ metabolism?

Several medications can influence NAD+ metabolism, including metformin, blood pressure medications, statins, and some antidepressants. Always consult your healthcare provider about potential interactions, especially if you’re on regular medications.

Can lifestyle factors deplete NAD+ faster than normal?

Yes. Chronic stress, excessive alcohol, UV radiation exposure, environmental toxins, and irregular sleep patterns can accelerate NAD+ depletion beyond normal aging. This makes healthy lifestyle choices important when optimizing NAD+ levels through supplementation.

Are there differences in NAD+ needs between men and women?

Research indicates sex-specific differences in NAD+ metabolism, with women showing different patterns of age-related decline compared to men. Hormonal changes during pregnancy and menopause can also affect NAD+ requirements, though more research is needed in this area.

Referenced Sources

1. https://www.cell.com/cell-metabolism/fulltext/S1550-4131(15)00266-1 ↩︎
2. https://pmc.ncbi.nlm.nih.gov/articles/PMC6740200/ ↩︎
3. https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2023.1285776/full ↩︎
4. https://academic.oup.com/endo/article/162/3/bqab006/6089118 ↩︎
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7. https://pmc.ncbi.nlm.nih.gov/articles/PMC8261484/ ↩︎
8. https://www.nature.com/articles/s41392-020-00311-7 ↩︎
9. https://pmc.ncbi.nlm.nih.gov/articles/PMC9154743/ ↩︎
10. https://pmc.ncbi.nlm.nih.gov/articles/PMC7752291/ ↩︎
11. https://www.nature.com/articles/s42255-018-0009-4 ↩︎
12. https://pubmed.ncbi.nlm.nih.gov/35479740/ ↩︎
13. https://www.nature.com/articles/ncomms12948 ↩︎
14. https://onlinelibrary.wiley.com/doi/10.1002/mrm.30227 ↩︎