What is NAD+?
NAD+ (Nicotinamide Adenine Dinucleotide) is not technically a peptide. It is a coenzyme found in every living cell. It still belongs in the longevity and biohacking research space, which is why it shows up alongside peptides like Epithalon and GHK-Cu in advanced protocols.
NAD+ is essential for two cellular processes: energy production (as an electron carrier in the mitochondrial TCA cycle and oxidative phosphorylation) and DNA repair (as a substrate for PARP enzymes and sirtuins). Here is the catch: NAD+ levels in human tissue fall by about 50% between age 20 and age 60. That decline tracks with the aging phenotype, including lower energy, weaker DNA repair, metabolic dysfunction and neurodegeneration.
Researchers including David Sinclair (Harvard Medical School) and Johan Auwerx (EPFL Lausanne) have put NAD+ decline at the centre of aging biology.
Effects, what does the research say?
Energy & Mitochondrial Function
NAD+ is the main electron carrier in the mitochondria; without it, the TCA cycle and oxidative phosphorylation cannot run. When NAD+ is restored:
- Mitochondrial biogenesis increases (more mitochondria, more energy capacity)
- SIRT1 and SIRT3 (sirtuin enzymes) are activated, which regulate metabolism and stress resistance
- Improved muscle function and exercise capacity documented in animal models
- Early human trials (NMN supplementation) show improved muscle insulin sensitivity
DNA Repair & Sirtuins
PARP enzymes, which are critical for DNA repair after damage, consume NAD+ rapidly when active. In aging cells with low NAD+, DNA damage accumulates faster than it can be repaired. Research shows:
- NMN supplementation restores NAD+ and improves DNA repair capacity in aged mice
- Sirtuin activation (SIRT1-7) regulates gene expression, inflammation, and cellular stress
- Caloric restriction's longevity effect is partly mediated through NAD+/sirtuin pathways
"NAD+ decline with age contributes to a metabolic signature of aging that includes dysregulation of energy metabolism, reduced stress resistance, and accumulation of cellular damage. Boosting NAD+ represents a promising strategy for aging intervention."
Verdin E (2015), NAD+ in Aging, Metabolism, and Neurodegeneration. Science. · PMID 26785480 ↗
NAD+ Precursors, NMN vs NR
Since direct oral NAD+ is poorly absorbed, precursors that convert to NAD+ in the body are most commonly used:
- NMN (Nicotinamide Mononucleotide): more direct precursor, better studied in recent human trials. Yoshino et al. (2021) showed NMN improved muscle insulin sensitivity in postmenopausal women with prediabetes.
- NR (Nicotinamide Riboside): well-studied, multiple human trials showing safe NAD+ elevation
- IV NAD+: bypasses absorption entirely for rapid systemic NAD+ elevation; used in clinical longevity protocols and addiction treatment
"NMN and NR are NAD+ intermediates with significant potential as therapeutic agents for aging-related conditions. Both have shown the ability to safely and substantially raise NAD+ levels in human subjects."
Yoshino M et al. (2021), Nicotinamide Mononucleotide Increases Muscle Insulin Sensitivity in Prediabetic Women. Science. · PMID 33888596 ↗
Dosage, what is being researched?
Important: There is no single universally approved human dosage protocol for NAD+ or its precursors. The following reflects what is documented in published clinical research; this is not medical advice.
| Form | Typical Dose | Protocol | Notes |
|---|---|---|---|
| NMN (oral) | 500-1000 mg/day | Daily, morning | Most human trial data |
| NR (oral) | 250-500 mg/day | Daily | Multiple safety trials |
| IV NAD+ | 500-1000 mg | 1-3× per week infusion | Clinical protocol |
| SC NAD+ | 100-300 mg | Every other day | Research protocol |
Storage
- NMN/NR (oral supplements): Cool, dry place away from light. Refrigeration extends shelf life.
- Injectable NAD+: Refrigerator (2-8 °C), protected from light.
- Reconstitute with sterile water or saline. Do not shake. Use within 24-48 hours of reconstitution for injectable forms.