The Science of NAD+ and Aging: What You Need to Know in 2026
If you follow longevity science, you've heard about NAD+. It has been called "the molecule of youth." But what is it, and what does it actually do inside a cell?
What is NAD+ and Why Does It Matter?
NAD+ (Nicotinamide Adenine Dinucleotide) is a coenzyme found in every living cell. It is essential for life — without it, cells cannot produce energy, repair DNA, or activate the sirtuin proteins. NAD+ serves three critical biological functions:
1. Cellular Energy Production
NAD+ is the central electron carrier in cellular respiration — the process by which mitochondria convert nutrients into ATP. Without adequate NAD+, this process becomes inefficient, reducing cellular energy output.
2. Sirtuin Activation
Sirtuins are seven proteins (SIRT1–SIRT7) that regulate gene expression, DNA repair, inflammation, and metabolic efficiency — often called "longevity proteins" because their activity is associated with healthy aging. Sirtuins are NAD+-dependent enzymes. They cannot function without NAD+.
3. DNA Repair
PARP enzymes are the body's primary DNA repair machinery. When DNA is damaged, PARP enzymes consume NAD+ to power the repair process. High levels of DNA damage can deplete NAD+ reserves, creating a loop in which lower NAD+ means impaired repair, which means more damage.
NAD+ Precursors
NAD+ precursors are compounds the body converts into NAD+. The two sold most widely are:
- NR (Nicotinamide Riboside) — the form used in Tru Niagen
- NMN (Nicotinamide Mononucleotide) — converts to NAD+ via a different pathway
ageLOC Youth contains neither NR nor NMN. It is a multi-ingredient formula built around Nu Skin's Youth Gene Cluster framework; see its product page and supplement label for Nu Skin's own description.
Where ageLOC Fits
ageLOC is Nu Skin's name for an ingredient platform organized around Youth Gene Clusters — the company's own term for groups of genes whose expression patterns shift with age. That is a separate subject from NAD+, which is a coenzyme rather than a gene. We make no claim on this page about what any ageLOC product does to NAD+ levels; for Nu Skin's own description of its products, read the product pages and labels.
Frequently Asked Questions
What is NAD+ and what does it do?
NAD+ is a coenzyme essential for cellular energy production, DNA repair, and sirtuin activation. It is consumed by DNA repair enzymes (PARPs) and regenerated through the cell's own biosynthesis pathways.
What is the best NAD+ supplement?
There isn't a single answer we can give you. NR and NMN are the two NAD+ precursors sold most widely, and they reach NAD+ by different pathways. Compare the labels, the doses and the cost per month, and talk to your healthcare provider.
Does ageLOC Youth raise NAD+ levels?
ageLOC Youth contains neither NR nor NMN. We make no claim about its effect on NAD+ levels. See the product page and the supplement label for Nu Skin's own description.
Related Reading
- What is NAD+? — the pillar page deep-dive on NAD+ biology
- What is NMN? — NMN vs NR comparison
- What is ageLOC R2? — the Day & Night supplement system
- The Complete Guide to Nutritional Supplements
- NuBodyRx Knowledge Base