What Is NAD+ Metabolism?
NAD+ is a coenzyme found in every living cell. It serves two critical roles: as an electron carrier that powers mitochondrial energy production, and as a signaling molecule that activates sirtuins — the proteins that regulate mitochondrial biogenesis, DNA repair, and stress resistance. NAD+ levels decline roughly 50% between ages 40 and 60, making this decline one of the most reproducible hallmarks of cellular aging.
Powers Energy
Electron carrier for the ETC
Activates Sirtuins
SIRT1, SIRT3, SIRT6 signaling
Declines With Age
~50% drop by age 60
Research Articles
NAD+ & Mitochondria: The Essential Connection
NAD+ is an essential cofactor for mitochondrial function — serving as an electron carrier in the electron transport chain and as a substrate for sirtuins that regulate biogenesis, repair, and stress resistance.
Read more →What Is NAD+? Structure, Function & Cellular Role
NAD+ is one of the most abundant and critical molecules in the body — discovered in 1906, its role has expanded from metabolic coenzyme to DNA repair, epigenetic regulation, and cellular signaling.
Read more →NAD+ & Aging: Why Levels Decline With Age
NAD+ levels fall roughly 50% between ages 40 and 60 — now recognized as a hallmark of aging, driven by CD38, PARP hyperactivation, and declining NAMPT.
Read more →NAD+ Biosynthesis Pathways Explained
Cells synthesize NAD+ through three distinct pathways — de novo, Preiss-Handler, and salvage — each using different precursors and central to evaluating NAD+-boosting strategies.
Read more →NMN Benefits: Research on Nicotinamide Mononucleotide
NMN is a direct NAD+ precursor showing promising results in animal aging models; human trials confirm it raises NAD+ with early signals for insulin sensitivity and exercise capacity.
Read more →Nicotinamide Riboside (NR) Benefits & Research
NR is a vitamin B3 form and NAD+ precursor with the most extensive human trial data, shown to safely elevate NAD+ by ~60% in older adults.
Read more →Niacin vs Niacinamide: NAD+ Precursor Comparison
Both forms of vitamin B3 boost NAD+ via different pathways — niacin uses Preiss-Handler (with flushing), niacinamide uses salvage — with distinct side-effect profiles.
Read more →NMN vs NR: Which NAD+ Precursor Does Research Support?
NMN and NR both enter the salvage pathway but differ in molecular steps, uptake mechanisms, and the depth of human data — which is better remains an open question.
Read more →NAD+ & Sirtuins: The Longevity Connection
Sirtuins are a family of seven NAD+-dependent enzymes (SIRT1–SIRT7) that regulate aging, metabolism, inflammation, and stress resistance — their activity directly limited by NAD+ availability.
Read more →NAD+ & DNA Repair: PARP Enzymes Explained
PARP enzymes are the largest consumers of cellular NAD+, using it to build poly(ADP-ribose) chains at DNA damage sites — critical first responders whose age-related hyperactivation drains NAD+.
Read more →NAD+ & Mitochondrial Function
NAD+ is indispensable for mitochondrial energy production — as an electron carrier in the ETC it directly controls ATP synthesis, and its age-related decline impairs mitochondrial function.
Read more →NAD+ & Circadian Rhythm Regulation
NAD+ levels oscillate with a circadian rhythm controlled by the CLOCK-BMAL1/NAMPT axis, creating a feedback loop with SIRT1 that links metabolic sensing to circadian timing.
Read more →How to Increase NAD+ Levels Naturally
Multiple evidence-based strategies may support NAD+ levels — exercise is the most validated intervention, while precursor supplementation and lifestyle factors offer additional avenues being actively researched.
Read more →NAD+, Exercise & Metabolic Health
Exercise is the most validated intervention for supporting NAD+ metabolism — directly upregulating NAMPT, the rate-limiting enzyme in NAD+ biosynthesis, and improving the NAD+/NADH ratio in skeletal muscle.
Read more →NAD+ Testing & Biomarkers
NAD+ testing has become commercially available, but measuring intracellular NAD+ accurately presents significant technical challenges — understanding the limitations of current testing methods is essential for interpreting results.
Read more →Coming Soon
Additional NAD+ metabolism research is in development.
NAD+ and Your Cellular Energy: Self-Assessment
Connect the science to your experience — which NAD+-related mechanisms may be most relevant to your energy, focus, and recovery.