Overview

Nicotinamide adenine dinucleotide (NAD+) is a small-molecule dinucleotide cofactor central to redox reactions, sirtuin activity, PARP-mediated DNA repair, and cyclic-ADP-ribose signalling. It is not a peptide, but is included in this reference set because it is routinely discussed and stacked alongside longevity peptides in the research literature.

NAD+ concentrations decline with age across many tissues, a pattern that motivated much of the recent interest in NAD+ boosters (nicotinamide riboside, NMN) and in exogenous NAD+ administration. Research on injectable NAD+ is smaller and more preliminary than the oral-precursor literature.

Mechanism (as reported in the literature)

  • Sirtuin cofactor. NAD+ is a required substrate for the sirtuin family of NAD-dependent deacetylases, which have been characterised across ageing, DNA-repair, and metabolic-regulation research.
  • PARP DNA-repair activity. PARPs consume NAD+ during DNA-damage responses; NAD+ availability has been characterised as a rate-limiting factor in some models of DNA-damage recovery.
  • Redox cycling. NAD+/NADH is a central redox couple in glycolysis, TCA cycle, and oxidative phosphorylation.
  • Mitochondrial biogenesis. Research indicates NAD+ availability influences PGC-1α-driven mitochondrial biogenesis pathways.

Research findings

  • Rodent ageing studies. NAD+ precursor supplementation studies (NMN, NR) report improved insulin sensitivity, endurance, and mitochondrial function in aged mice.
  • Human oral-precursor trials. Randomised trials of nicotinamide riboside and NMN in adults have reported increases in whole-blood NAD+ levels; functional-outcome data remain limited (Martens et al., 2018; PMID 29497171).
  • Injectable NAD+ clinical data. Rigorous randomised trials of injectable NAD+ are limited; reported protocols are drawn largely from clinic writeups and small case series.

Common dosing (from reported protocols)

Reported subcutaneous NAD+ protocols vary widely — from short daily courses of 50–100 mg per administration to twice-weekly 100–250 mg administrations. Intravenous infusion protocols in clinic settings typically use higher totals over multi-hour sessions.

Injection-site reactions and flushing at higher doses are commonly reported.

Reconstitution

A 500 mg vial reconstituted with 5 mL of bacteriostatic water yields a 100,000 mcg/mL (100 mg/mL) solution.

  • 50 mg (50,000 mcg) = 0.50 mL = 50 units on a U-100 syringe
  • 100 mg = 1.00 mL = 100 units

Storage

Reconstituted NAD+ is refrigerated at 2–8 °C, protected from light, and reported as usable for approximately 14 days.

  • MOTS-c — a mitochondrial-derived peptide with overlapping metabolic-signalling context.
  • Epithalon — a longevity-associated tetrapeptide.

Common stacks

References

  • Martens, C. R., et al. (2018). “Chronic nicotinamide riboside supplementation is well-tolerated and elevates NAD+ in healthy middle-aged and older adults.” Nature Communications, 9(1). PMID 29497171.
  • Yoshino, J., Baur, J. A., Imai, S. (2018). “NAD+ intermediates: the biology and therapeutic potential of NMN and NR.” Cell Metabolism, 27(3). PMID 29249689.
  • Rajman, L., Chwalek, K., Sinclair, D. A. (2018). “Therapeutic potential of NAD-boosting molecules: the in vivo evidence.” Cell Metabolism, 27(3). PMID 29514064.