What is NAD+? Why it declines with age

If you’ve been following the latest research in healthy aging and longevity, you’ve likely come across the term NAD+. If not, don’t worry. The below guide will help explain what NAD+ is and why it matters for your health especially as you age.   

Understanding the role of NAD+ in the human body  

What is NAD+ (nicotinamide adenine dinucleotide)? 

NAD+ stands for nicotinamide adenine dinucleotide. It’s a vital coenzyme found in nearly every living cell that helps facilitate different chemical reaction essential for energy production, cellular repair and metabolic function.  

Why your cells depend on it 

Now that we have covered what is NAD+, let’s dive into what it does in the body and why your cells depend on it. 

#1 Energy production: 

Inside your mitochondria, NAD+ acts like a delivery service for energy. It picks up high-energy electrons from the food you eat and the air we breathe and drops them off at the machinery that makes ATP, the fuel your body runs on. Without enough NAD+, this energy production slows…

#2 Cellular repair & maintenance: 

NAD+ activates enzymes such as sirtuins and PARPs, which help repair damaged DNA and maintain overall cell health.

#3  Metabolic regulation:

NAD+ also plays a vital role in controlling how cells process fats, carbohydrates, and amino acids, ensuring your body can adapt its energy use depending on your needs and nutrient availability.

#4 Cell signaling & stress response:

NAD+ influences signaling pathways that regulate inflammation, oxidative stress, and cell survival, helping cells respond to challenges and maintain stability. 

Without enough NAD+, your cells can’t operate at full capacity and over time, that can show up as fatigue, brain fog and signs of aging. 

How NAD+ levels change as you age

The aging curve: when decline begins

NAD+ is essential to life, but here’s the catch: your natural supply doesn’t stay constant as you age. NAD+ levels start to decline around age 30 and some research has found that by the time you're 40 you could have lost up to 50% of your natural supply. 

What depletes NAD+ stores over time  

As we age, we use more NAD+ and it is not restored as efficiently. It’s essentially a supply and demand problem. As we age, we use more NAD+ (increased demand) for cell function and repair but evidence suggests it may not be restored as efficiently as we age (decreased production). 

The result? Your cells are left running on a tighter and lower NAD+ budget. 

Signs of declining NAD+ levels

Fatigue, brain fog, and sign of aging  

NAD+ is critical to how your cells operate. Lower levels impact energy production, DNA repair, and cellular communication. In fact, NAD+ decline is considered one of the Hallmarks of Aging, a core biological process that drives age-related decline. Put it simply, when NAD+ drops with age… you can feel it. 

Fatigue: When NAD+ levels decline, mitochondria produce less ATP. ATP is our energy currency, when the body produces less, our physical and mental energy is drained.  

Mental fog:  The brain is hungry for energy! Declining NAD+ levels can impact energy production in brain cells, potentially contributing to brain fog and impacting focus. 

Visible signs of aging:  NAD+ is involved in multiple cellular processes. As noted above, without adequate levels, mitochondria produce less ATP, reducing the energy available for repair, regeneration, and daily cellular function. Additionally, when NAD+ declines, cells become more vulnerable to environmental stressors and low-grade inflammation, often referred to as “inflammaging.” In the skin, reduced NAD+ contribute to wrinkles and loss of elasticity. In short, low NAD+ impacts energy output, repair systems, and tissue regeneration. This decline impacts both visible signs (wrinkles, muscle loss, slower healing) and functional signs (fatigue, cognitive decline, reduced resilience).

With all this said, it’s no surprise that replenishing lost NAD+ is becoming a major focus in healthy aging science. Cellular research has shown that replenishing lost NAD+ levels can help improve daily energy, mental clarity and metabolic health, all of which are essential to feeling your best with age. 

The smarter approach to NAD+ support 

After reading all of this, you are probably thinking – great! I’ll just consume foods rich in NAD+. Unfortunately, NAD+ is a large molecule that doesn’t cross cell membranes well. Therefore, taking NAD+ directly does not work as the digestive system quickly degrades it before it can reach our cells. 

That’s why supplementation focuses on NAD+ precursors, smaller building blocks like niacin, nicotinamide riboside (NR), and nicotinamide mononucleotide (NMN) that your body can naturally convert into NAD+. Your cells also need to be able to use that NAD+ efficiently. If your mitochondria are underperforming, much of that boosted NAD+ can go to waste. 

That’s why we created MitoQ NAD+ Dual Action, a formulated with clinically-studied ingredients that don’t just raise NAD+ levels, but it also helps to optimize how your mitochondria utilize the extra supply. 

The MitoQ formula pairs two NAD+ precursors - niacin and nicotinamide riboside (NR) with cellular antioxidants—Resveratrol and PQQ—that help prime and protect mitochondria. These two antioxidants not only support mitochondrial performance but also encourage the creation of new mitochondria, giving your cells more “engines” to turn NAD+ into energy. 

The result? More energy. Sharper focus. Increased support for healthy aging from within. Because at the end of the day, it’s not just about having more NAD+. It’s about smarter NAD+.