NAD+ Research Guide: Coenzyme, Sirtuins and Aging

NAD+ is a coenzyme found in every living cell, and its role in aging biology is one of the most active areas of longevity research. This guide covers what NAD+ does, why its decline with age draws so much study, and the main research questions.

What is NAD+?

Nicotinamide adenine dinucleotide (NAD) exists in an oxidized form, NAD+, and a reduced form, NADH. It is a dinucleotide: two nucleotides, one containing adenine and one containing nicotinamide, joined through their phosphate groups.

Strictly speaking, NAD+ is a coenzyme, not a peptide. It sits in Ares Labs’ Longevity Research category because it is so often studied alongside peptides in aging research.

Two jobs: electron carrier and signaling substrate

A 2015 review in Science describes NAD+’s two roles [1]:

• Redox coenzyme: NAD+ and NADH carry electrons between reactions in glycolysis, the citric-acid cycle and mitochondrial respiration. That makes NAD+ central to how cells produce energy.
• Co-substrate: NAD+ is consumed by enzymes such as the sirtuins (protein deacylases tied to metabolic regulation) and PARPs (poly-ADP-ribose polymerases involved in DNA repair). These enzymes use up NAD+, so cells have to keep making more.

The age-related decline

A key observation in the field is that cellular NAD+ levels change with age. A 2018 Cell Metabolism review states that NAD+ levels decline steadily with age, and that restoring NAD+ in old or diseased animals has improved health measures and extended lifespan in those models [2]. Reviews in Nature Reviews Molecular Cell Biology and Nature Metabolism go deeper into how NAD+ is made, used and recycled [3, 4].

Research approaches include direct NAD+ and its precursors, such as nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN), as well as inhibitors of NAD+-consuming enzymes like CD38. A 2025 review in Nature Aging covers how these strategies are being tested, and the challenges of translating them [5].

Where the evidence stops

Results in yeast, worms and rodents have been striking, but human data are still limited and mixed. Reviewers stress that much remains unknown about how NAD+ is taken up and distributed across tissues [5]. Ares Labs makes no claims about effects in people.

Laboratory handling

• NAD+ is sensitive to heat, moisture and light, and is less stable in solution at alkaline pH. Store lyophilized material cold and dry.
• Make fresh solutions where possible and log lot numbers.
• Confirm identity and purity against the batch Certificate of Analysis.

FAQ

Is NAD+ a peptide?
No. It is a dinucleotide coenzyme, often studied alongside peptides in longevity research.

What’s the difference between NAD+, NMN and NR?
NMN and NR are precursors that cells convert into NAD+. Ares Labs supplies NAD+ itself.

View NAD+ research vials and the current COA →

References

1. Verdin E. NAD⁺ in aging, metabolism, and neurodegeneration. Science. 2015;350(6265):1208-1213. PMID 26785480
2. Rajman L, Chwalek K, Sinclair DA. Therapeutic Potential of NAD-Boosting Molecules: The In Vivo Evidence. Cell Metab. 2018;27(3):529-547. PMID 29514064
3. Covarrubias AJ, et al. NAD(+) metabolism and its roles in cellular processes during ageing. Nat Rev Mol Cell Biol. 2021. PMID 33353981
4. Katsyuba E, et al. NAD(+) homeostasis in health and disease. Nat Metab. 2020. PMID 32694684
5. Zhang J, et al. Emerging strategies, applications and challenges of targeting NAD(+) in the clinic. Nat Aging. 2025. PMID 40926126

For laboratory research use only. Not for human or animal consumption. This article summarizes published research for reference. It is not medical advice and makes no claim that any product treats, cures or prevents any condition.