What is NAD+? The Complete Guide to NAD+ and Cellular Aging

NAD+ (Nicotinamide Adenine Dinucleotide) is a coenzyme found in every living cell that is essential for cellular energy production, DNA repair, and the activation of sirtuins — proteins often called “longevity proteins” because of their role in regulating how cells age. NAD+ is produced naturally in the body, and its levels fall as we get older.

In one sentence: NAD+ is the molecule that powers your cells' energy production and repair systems, and its age-related decline is widely studied as a driver of the aging process itself.

Key Facts About NAD+

• Full name: Nicotinamide Adenine Dinucleotide
• Type: Coenzyme (helper molecule) found in every living cell
• Primary roles: Cellular energy production (ATP), DNA repair (via PARP enzymes), sirtuin activation
• Key enzymes that consume NAD+: PARP (DNA repair), CD38 (inflammation), SARM1
• Rate-limiting biosynthesis enzyme: NAMPT
• Best-studied precursors: NR (Nicotinamide Riboside) and NMN (Nicotinamide Mononucleotide)
• Longevity proteins activated by NAD+: Sirtuins (SIRT1–SIRT7)

What is NAD+?

NAD+ stands for Nicotinamide Adenine Dinucleotide — a coenzyme found in every cell of every living organism. It exists in two forms: NAD+ (the oxidized form) and NADH (the reduced form). Together, they cycle back and forth as NAD+ accepts electrons and becomes NADH, then donates those electrons and returns to NAD+.

This cycling is fundamental to cellular energy production. Without NAD+, cells cannot generate ATP — the energy currency that powers virtually every biological process in the body. But NAD+ does more than energy metabolism. It is a critical substrate for sirtuins (SIRT1–SIRT7) and for PARP enzymes that repair damaged DNA.

What Does NAD+ Do in the Body?

1. Cellular Energy Production

NAD+ is the central electron carrier in cellular respiration — the process by which mitochondria convert nutrients into ATP. NAD+ accepts electrons from glucose and fatty acid metabolism, becoming NADH, which then drives ATP synthesis via the electron transport chain.

2. Sirtuin Activation (Longevity Proteins)

Sirtuins are a family of seven proteins (SIRT1–SIRT7) that regulate gene expression, DNA repair, inflammation and metabolic efficiency. They are NAD+-dependent enzymes — they cannot function without NAD+.

3. DNA Repair via PARP Enzymes

PARP (Poly ADP-Ribose Polymerase) enzymes are part of the body's DNA repair machinery. When DNA is damaged — by UV radiation, oxidative stress or normal metabolic processes — PARP enzymes consume NAD+ to power the repair process.

Why Does NAD+ Decline with Age?

Several mechanisms are thought to contribute:

• Increased NAD+ consumption: more DNA damage, inflammation and oxidative stress, all of which consume NAD+ through PARP, CD38 and SARM1
• Reduced NAD+ biosynthesis: NAMPT, the rate-limiting enzyme in the NAD+ salvage pathway, becomes less active
• Mitochondrial changes: less efficient NAD+ cycling
• Chronic inflammation: inflammatory signalling activates CD38, an enzyme that degrades NAD+

How to Support NAD+ Levels

NAD+ Precursor Supplementation

• NR (Nicotinamide Riboside): the NAD+ precursor with the largest published human trial base to date
• NMN (Nicotinamide Mononucleotide): one step closer to NAD+ in the biosynthesis pathway; growing human evidence base. See: What is NMN?
• Niacin (Vitamin B3): the original NAD+ precursor; associated with flushing at higher doses. Found in LifePak Nano
• Niacinamide: non-flushing form of B3; also used topically in skincare

NuBodyRx does not sell a standalone NR or NMN supplement. This section is here because it is the question people ask, not because we have something to sell you on it.

Lifestyle Factors That Support NAD+

• Exercise: activates AMPK and SIRT1
• Intermittent fasting: lowers metabolic demand and inflammation
• Reducing alcohol: alcohol metabolism consumes NAD+ and disrupts the NAD+/NADH ratio
• Sun protection: UV radiation causes DNA damage that activates PARP and depletes NAD+
• Consistent sleep: NAD+ levels follow circadian rhythms

NAD+ and Skin Aging

NAD+ decline has consequences for skin: cell turnover slows, collagen synthesis decreases, DNA repair in skin cells becomes less efficient, and skin barrier function weakens. This is why comprehensive anti-aging approaches — like the ageLOC technology platform — work on cellular function alongside topical skincare.

NAD+ and the ageLOC Range

Nu Skin's ageLOC technology targets Youth Gene Clusters, which Nu Skin defines as “functional groups of genes that regulate how we appear to age.” People building a broader routine often combine LifePak Nano (which includes vitamin B3) with ageLOC Youth.

Frequently Asked Questions About NAD+

What is the difference between NAD+ and NADH?

NAD+ is the oxidized form that accepts electrons during metabolism; NADH is the reduced form that donates electrons to generate ATP. Both are essential and cycle continuously in cellular energy production.

Can you take NAD+ directly as a supplement?

NAD+ itself is poorly absorbed orally — it is broken down in the digestive tract before it can enter cells. NAD+ precursors (NR, NMN, niacin) are used instead, as these smaller molecules are absorbed and converted to NAD+ inside cells.

What is the difference between NR and NMN?

Both are NAD+ precursors. NMN is one step closer to NAD+ in the biosynthesis pathway. NR has more published human clinical trial data. See: What is NMN?

How long does it take for NAD+ supplements to work?

This varies from person to person and by product, and we are not going to put a figure on it. Supplements of any kind are judged over months rather than days.

How can I support NAD+ levels naturally?

Exercise, intermittent fasting, reducing alcohol, protecting skin from UV radiation and consistent sleep all support NAD+ levels.

*These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease.