NAD+ (Nicotinamide Adenine Dinucleotide, oxidized form) is a coenzyme present in every living cell and essential for over 500 enzymatic reactions in human biology. It is not a peptide in the strict sense but is included in the longevity peptide catalog due to its central role in cellular energy metabolism and its prominence in aging research. NAD+ exists in two forms: the oxidized form (NAD+) that serves as an electron acceptor in catabolic reactions, and the reduced form (NADH) that donates electrons to the mitochondrial electron transport chain for ATP production. Intracellular NAD+ levels decline approximately 50% between ages 40 and 60, and this decline has been identified as a key driver of age-related metabolic dysfunction.

NAD+ functions as an essential substrate for three families of enzymes that are central to cellular maintenance: sirtuins (SIRT1-7), which regulate gene expression, DNA repair, and metabolic homeostasis; poly-ADP-ribose polymerases (PARPs), which repair single-strand and double-strand DNA breaks; and CD38/CD157 ectoenzymes, which regulate cellular calcium signaling and immune function. All three enzyme families consume NAD+ as a substrate (not just a cofactor), meaning they deplete the cellular NAD+ pool with every reaction. As NAD+ levels decline with age, competition between sirtuins and PARPs for the shrinking NAD+ supply forces the cell into triage — prioritizing acute DNA repair (PARPs) at the expense of the long-term maintenance functions (sirtuins) that prevent metabolic decline.

Research on NAD+ restoration has produced compelling results across multiple domains. Studies demonstrate that raising NAD+ levels improves mitochondrial function, enhances DNA repair capacity, restores sirtuin activity, improves insulin sensitivity, reduces age-related inflammation (inflammaging), and extends healthspan in animal models. Clinical trials of NAD+ precursors (NMN, NR) have shown improvements in muscle function, cardiovascular markers, and metabolic parameters in human subjects. Direct intravenous NAD+ administration — which the lyophilized powder supports after reconstitution — bypasses the precursor conversion steps and delivers the active molecule directly.

NAD+ is suited for researchers investigating cellular energetics, mitochondrial function, DNA repair, sirtuin biology, and age-related metabolic decline. It is a cornerstone compound for comprehensive longevity protocols and pairs synergistically with SS-31 (mitochondrial membrane stabilization) and Epitalon (telomere maintenance) for multi-pathway anti-aging research.

Reconstitute the 1000mg vial with 10ml bacteriostatic water (yielding 100mg/ml). NAD+ can be administered via subcutaneous injection or intravenous infusion, though subcutaneous is the most common research route for lyophilized formulations. Typical subcutaneous research dosing ranges from 50-200mg per day. NAD+ has a plasma half-life of approximately 30-45 minutes, but intracellular effects persist as the molecule is phosphorylated and incorporated into cellular metabolic pools. Store reconstituted solution at 2-8C and protect from light — NAD+ is light-sensitive and will degrade if exposed to UV. Lyophilized powder should be stored at -20C for long-term preservation. The 1000mg vial provides 5-20 days of research at standard subcutaneous dosing.