The Role of NAD+ in Cellular Metabolism
Nicotinamide adenine dinucleotide (NAD+) is a coenzyme present in every living cell, serving as a critical electron carrier in mitochondrial oxidative phosphorylation — the primary process by which cells generate ATP, the universal energy currency of biology. Beyond energy production, NAD+ is a required substrate for sirtuins (SIRT1-7), a family of enzymes that regulate DNA repair, gene expression, inflammation, and circadian rhythm. It also fuels poly(ADP-ribose) polymerases (PARPs), which are essential for maintaining genomic stability.
Research has consistently shown that NAD+ levels decline with age — by approximately 50% between the ages of 40 and 60. This decline is associated with mitochondrial dysfunction, impaired DNA repair capacity, increased cellular senescence, and the chronic low-grade inflammation often referred to as "inflammaging." The correlation between NAD+ depletion and age-related disease has made NAD+ restoration one of the most actively researched areas in longevity science.
Approaches to NAD+ Restoration
Several strategies exist for replenishing NAD+ levels. Oral precursors such as nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN) are converted to NAD+ through salvage pathways and have shown promise in both animal and early human studies. Intravenous NAD+ infusion delivers the coenzyme directly into the bloodstream, bypassing gastrointestinal absorption limitations and achieving rapid elevation of intracellular NAD+ levels.
A landmark 2022 study published in Nature Metabolism demonstrated that NMN supplementation improved insulin sensitivity and muscle function in prediabetic women. Meanwhile, IV NAD+ protocols have been used in clinical settings for metabolic optimisation, cognitive support, and recovery from substance use disorders, where NAD+ depletion is particularly pronounced. The optimal route, dose, and frequency of NAD+ restoration remain areas of active investigation.
Practical Considerations
At DOSIST, NAD+ protocols are administered under medical supervision with pre-treatment assessment and ongoing monitoring. IV infusions typically range from 250–750 mg per session, delivered over 2–4 hours to minimise flushing and discomfort. Sublingual and subcutaneous formulations are also available for maintenance between infusion sessions. Patients commonly report improved mental clarity, physical energy, and sleep quality, though individual responses vary.
- NAD+ is essential for ATP production, DNA repair, and sirtuin activation
- Levels decline approximately 50% between ages 40–60
- IV administration achieves rapid intracellular NAD+ elevation
- Medical supervision ensures safe dosing and monitoring
