What is NAD+?
NAD+ stands for nicotinamide adenine dinucleotide. It's a coenzyme — think of it as a tiny molecular helper — found inside every living cell. Without it, cells can't produce energy or repair themselves properly.
Here's the catch: NAD+ levels naturally fall as we get older. Research has found this decline happens in human skin, blood, liver, muscle, and brain tissue over time.[1] That age-related drop has made NAD+ one of the most talked-about molecules in longevity science.
NAD+ is classified here as a research compound. It is not approved as a medicine, and nothing on this page is medical advice.
How NAD+ Works
Think of NAD+ like a rechargeable battery inside your cells. It shuttles electrons around during metabolism — accepting them in one reaction, dropping them off in another. That shuttle is how your cells turn food into usable energy.[4]
But NAD+ does more than just energy production. It also powers a family of proteins called sirtuins — enzymes that help repair DNA, regulate gene expression, and keep mitochondria (your cells' power plants) running cleanly.[2] When NAD+ levels are high, sirtuins stay active. When NAD+ drops, that protective activity fades.[3]
There's also a villain in this story: an enzyme called CD38. CD38 consumes NAD+ rapidly, and its activity ramps up with age — one reason NAD+ levels decline over time.[3] Researchers are now exploring ways to block CD38 to help preserve NAD+ in tissues.
What the Research Shows
Most of the exciting early findings on NAD+ come from cell and animal studies, with human trials still catching up. Here's a plain-language summary of what the current science suggests:
- Aging and longevity: NAD+ metabolism is tightly linked to several biological hallmarks of aging, including cellular senescence (the process where damaged cells stop dividing but don't die). Low NAD+ can trigger DNA damage and mitochondrial dysfunction that push cells into a senescent state.[5]
- Brain health: A decline in NAD+ has been observed during normal aging, and since aging is the top risk factor for neurological disorders, researchers are actively studying whether restoring NAD+ could protect neurons. Early evidence suggests it may help counter oxidative stress and mitochondrial problems in the brain.[2]
- Skin aging: Lab work on human skin fibroblasts found that exogenous (externally applied) NAD+ offered protection against both UV-induced aging and the natural aging process. Combining NAD+ with compounds that block CD38 significantly boosted those protective effects, improving sirtuin activity, autophagy, and mitochondrial function.[3]
- Joint health: A 2025 study engineered NAD+-loaded hydrogel microspheres and injected them into the joints of aged mice. The treatment reduced cartilage cell senescence, calmed joint inflammation by shifting immune cells from a pro-inflammatory to an anti-inflammatory state, and improved joint lubrication and movement.[6]
- Gut inflammation: NAD+ metabolism plays a complex role in inflammatory bowel disease. Components of NAD+ biosynthesis are elevated in IBD — but researchers are still working out whether that's the body trying to fight back, or part of the problem.[4]
- Human clinical trials: A growing number of human trials using NMN — a direct precursor that the body converts into NAD+ — are underway. Early results look promising for safety and some anti-aging markers, but researchers note that most robust evidence still comes from cell and animal models.[1]
What NAD+ Is Being Studied For
- Age-related cellular decline and senescence[5]
- Neurological protection and brain aging[2]
- Skin anti-aging applications[3]
- Joint degeneration and osteoarthritis[6]
- Gut barrier integrity and inflammation[4]
- Overall metabolic health and energy production[1]
How NAD+ Is Dosed in Research
Dosing for NAD+ in research settings varies considerably depending on the administration route (intravenous, intra-articular, topical, or oral precursor), the model being studied, and the specific research question. Because there is no single established protocol, researchers are encouraged to consult the dosage chart on this page for a structured reference overview, and to use the calculator to work out weight-based or concentration-based figures for their specific study design. Always refer to peer-reviewed literature and institutional guidelines when designing any research protocol.
Mixing and Storing NAD+
NAD+ in powder form is generally water-soluble, which makes reconstitution straightforward compared to many peptides. For research preparations, bacteriostatic water or sterile water is commonly used as the solvent. Add the solvent slowly along the side of the vial — don't shake it, just gently swirl until fully dissolved. Once reconstituted, NAD+ solutions should be kept refrigerated (2–8 °C) and shielded from light, as NAD+ can degrade with heat and UV exposure. Dry, unreconstituted powder should be stored in a cool, dark place — a freezer is ideal for long-term storage. Always label vials with the date of reconstitution and discard any solution that looks cloudy or discolored. These are general research-handling guidelines; follow your institution's specific protocols.
Sources
- The Safety and Antiaging Effects of Nicotinamide Mononucleotide in Human Clinical Trials: an Update. — Advances in nutrition (Bethesda, Md.), 2023. PMID 37619764.
- Nicotinamide Adenine Dinucleotide (NAD(+))-Dependent Signaling in Neurological Disorders. — Antioxidants & redox signaling, 2023. PMID 37288742.
- Novel Approach to Skin Anti-Aging: Boosting Pharmacological Effects of Exogenous Nicotinamide Adenine Dinucleotide (NAD(+)) by Synergistic Inhibition of CD38 Expression. — Cells, 2024. PMID 39513906.
- Nicotinamide adenine dinucleotide metabolism: driving or counterbalancing inflammatory bowel disease? — FEBS letters, 2023. PMID 36310388.
- NAD metabolism: Role in senescence regulation and aging. — Aging cell, 2024. PMID 37424179.
- Nicotinamide Adenine Dinucleotide-Loaded Lubricated Hydrogel Microspheres with a Three-Pronged Approach Alleviate Age-Related Osteoarthritis. — ACS nano, 2025. PMID 40315404.