NAD+, NADH and Skin Ageing: Understanding Cellular Energy Without the Hype
NAD has become one of the most talked-about molecules in longevity and wellness. It is often described as a cellular “energy molecule”, a DNA-repair molecule or even an anti-ageing switch. Those descriptions contain a piece of the truth, but they can also oversimplify a complex area of biology.
NAD is essential to life. It helps cells transfer electrons, produce usable energy and support enzymes involved in cellular stress responses and DNA repair. However, the fact that a molecule is biologically important does not automatically mean that taking or receiving more of it will reverse ageing, improve skin quality or deliver a visible cosmetic result.
This article explains the difference between NAD, NAD+ and NADH, how the NAD+/NADH cycle supports cellular metabolism, what it may mean for ageing skin and where current human evidence remains uncertain.
Key Takeaways
- NAD is the general name for a coenzyme that cycles mainly between NAD+ and NADH.
- NAD+ is the oxidised form that can accept electrons; NADH is the reduced form that carries high-energy electrons.
- The cycle between NAD+ and NADH helps cells convert nutrients into ATP, the immediately usable form of cellular energy.
- NAD+ also acts as a substrate for enzymes involved in DNA repair, stress responses and gene regulation.
- Laboratory and animal research is biologically compelling, but evidence that NAD-targeted interventions produce meaningful anti-ageing or cosmetic skin benefits in humans remains limited and inconsistent.
- Healthy-looking skin depends on many interacting layers and pathways; NAD biology is one part of that system, not a complete anti-ageing strategy.
What Do NAD, NAD+ and NADH Mean?
NAD stands for nicotinamide adenine dinucleotide. It is a coenzyme found in every living cell. “Coenzyme” means that it helps enzymes carry out chemical reactions but is not itself a source of calories or energy.
The term NAD is often used as an umbrella label for a redox pair—two forms of the same molecule that repeatedly convert into one another:
- NAD+: the oxidised form. It is ready to accept a hydride, which carries two electrons and one proton.
- NADH: the reduced form. It has accepted those electrons and can carry them to another reaction.
The plus sign in NAD+ does not mean “better”, “more powerful” or “more energy”. It refers to the molecule’s chemical charge in its oxidised state. Likewise, the H in NADH indicates the reduced, electron-carrying form.
NAD+ vs NADH at a Glance
Feature | NAD+ | NADH |
Chemical state | Oxidised | Reduced |
Main redox role | Accepts electrons | Carries and donates electrons |
Energy metabolism | Supports reactions that break down nutrients | Transfers electrons toward ATP production |
Relationship | Becomes NADH when reduced | Becomes NAD+ when oxidised |
Simple analogy | An available carrier | A loaded carrier |
The Chemistry Behind the Difference
Oxidation and reduction describe the transfer of electrons. During many metabolic reactions, NAD+ accepts a hydride from another molecule and becomes NADH. NADH can then donate those electrons elsewhere and return to NAD+.
Simplified redox equation NAD+ + 2 e- + H+ ⇌ NADH |
The NAD+/NADH ratio varies between cellular compartments and changes with metabolic activity. It is better understood as part of a dynamic redox system than as a single wellness score. A blood measurement also does not necessarily describe what is happening inside the mitochondria or skin cells.
How the NAD+/NADH Cycle Supports Cellular Energy
When carbohydrates, fats and proteins are metabolised, NAD+ accepts electrons during glycolysis, the citric acid cycle and other pathways. This produces NADH. Inside mitochondria, NADH transfers electrons to the electron transport chain. The resulting energy gradient helps cells manufacture ATP.
ATP is the molecule cells use directly to power activities such as protein synthesis, ion transport, cellular maintenance and renewal. NADH helps transport the electrons used in this process, while NAD+ must be regenerated so metabolism can continue.
Calling NAD+ an “energy molecule” is therefore convenient but incomplete. NAD+ does not energise a cell in the same way that fuel powers an engine. It is part of the chemical system that allows cells to extract and transfer energy from nutrients.
NAD+ Does More Than Support Energy Metabolism
NAD+ is also consumed by several families of enzymes. These include PARPs, which participate in DNA-damage responses; sirtuins, which influence metabolic and stress-response pathways; and CD38, an enzyme involved in NAD metabolism and cellular signalling.
These pathways are among the reasons NAD biology attracts interest in ageing research. However, terms such as “DNA repair” or “longevity pathway” should not be converted into promises that an NAD-targeted product will repair a person’s DNA, extend life or reverse visible ageing. Mechanistic plausibility is not the same as a proven clinical outcome.
What Does NAD Biology Mean for the Skin?
Skin is a metabolically active organ. Keratinocytes in the epidermis continually renew, fibroblasts in the dermis maintain extracellular matrix, and immune, pigment and vascular cells respond to environmental stress. All of these cells require energy and balanced redox chemistry.
Epidermal renewal and barrier function
The epidermis relies on coordinated cell division, differentiation and lipid production to maintain the skin barrier. NAD-dependent metabolism is relevant to these processes at a cellular level. That does not mean an external NAD intervention has been proven to restore a damaged barrier in people.
Dermal fibroblasts and structural ageing
Fibroblasts produce collagen, elastin and other components of the dermal matrix. Ageing fibroblasts may show altered mitochondrial function, stress responses and senescence. NAD-related pathways are being studied in this context, but human evidence linking NAD-targeted interventions to meaningful increases in collagen or visible skin tightening is not established.
UV exposure and DNA-damage responses
Ultraviolet radiation can damage cellular DNA and accelerate pigmentation, texture change and collagen breakdown. NAD+ is used by enzymes involved in DNA-damage responses. This biological relationship does not replace established photoprotection: broad-spectrum sunscreen, protective clothing, shade and avoidance of excessive UV remain foundational for skin health.
Do NAD+ Levels Decline With Age?
Animal studies and measurements in selected human tissues suggest that NAD metabolism changes with age. Proposed contributors include reduced synthesis, increased consumption by enzymes such as CD38, inflammation, oxidative stress and mitochondrial dysfunction.
The human picture is more complicated than the common claim that “NAD falls by a fixed percentage after a certain age”. A 2025 review in Nature Metabolism concluded that consistent evidence of an age-related decline in human NAD+ has been demonstrated in only a limited number of studies and may differ between tissues. Exact percentage claims should therefore be treated cautiously.
Can Increasing NAD+ Reverse Skin Ageing?
What the evidence supports Research supports NAD as an essential participant in cellular metabolism and ageing-related pathways. It does not yet establish that increasing NAD through a supplement, injection or infusion reliably reverses skin ageing, improves collagen, increases energy or produces a predictable cosmetic result in humans. |
Studies of NAD precursors can show that some interventions alter blood or tissue metabolites. That is a biological outcome, but it is not automatically a patient-important outcome. Trials must separately demonstrate whether people experience meaningful improvements in health, function or skin appearance.
Recent reviews of human interventions describe clear biological activity but inconclusive or limited clinical effectiveness for general anti-ageing and wellness outcomes. Evidence specific to visible skin ageing is even less developed. Larger, longer and well-controlled human trials are needed.
Why Skin Ageing Cannot Be Reduced to One Molecule
Visible facial ageing develops across multiple levels: the epidermal barrier and pigmentation, the dermal collagen and elastin network, subcutaneous volume, retaining ligaments, fascia and facial muscle. UV exposure, hormones, inflammation, genetics, lifestyle and repeated facial movement also contribute.
BalaBala’s approach to anti-ageing therefore focuses on assessment across the skin and supporting structures rather than presenting one molecule, device or procedure as a complete solution. A consultation may consider skin quality, pigmentation, laxity, volume change and muscle-related ageing before appropriate options are discussed.
For patients interested in understanding their skin condition, VISIA skin analysis can support objective documentation of features such as pigmentation, redness and texture. Explore BalaBala’s broader anti-ageing treatments in Adelaide.
What Supports Cellular and Skin Health Now?
While NAD research continues, the strongest practical foundations for healthy ageing remain familiar. They do not target a single molecule, but they support the systems in which cellular metabolism operates:
- regular physical activity appropriate for the individual
- adequate sleep and management of sleep disorders
- a balanced diet that provides sufficient protein, fibre and micronutrients
- not smoking and limiting excessive alcohol consumption
- daily UV protection and avoidance of tanning
- management of diagnosed medical conditions with qualified health professionals
- evidence-based skin and aesthetic treatment selected after individual assessment
These measures are not guaranteed to “boost NAD” to a particular level, and they should not be promoted with that promise. Their value comes from broader evidence for metabolic, cardiovascular, sleep and skin health.
Important Australian Regulatory Context
In February 2026, the Therapeutic Goods Administration stated that NAD, NAD+ and NADH were not permitted ingredients in listed medicines. The TGA also advised that therapeutic goods referring to NAD, NAD+, NADH or NMN must be included in the Australian Register of Therapeutic Goods unless exempted or otherwise authorised.
The regulatory position of a specific product depends on its ingredients, route, claims and lawful supply pathway. Educational content can still be considered advertising when a reasonable consumer would understand it as promoting a therapeutic good. Consumers should not assume that “natural”, “compounded” or “available in a clinic” means a product has been evaluated by the TGA for quality, safety and effectiveness.
Anyone considering a therapeutic product should speak with an appropriately qualified health professional and ask about the product, evidence, risks, alternatives and legal supply pathway. This article is general education and is not an advertisement or recommendation for an NAD-related therapeutic good.
Frequently Asked Questions
Is NAD the same as NAD+?
NAD is often used as a general label for the NAD redox system. NAD+ is specifically the oxidised form, while NADH is the reduced, electron-carrying form.
Is NADH better than NAD+?
No. Cells need both forms and the ability to cycle between them. NAD+ accepts electrons and NADH carries them; neither is universally better.
What does the plus sign in NAD+ mean?
It describes the molecule’s positive charge in its oxidised state. It is a chemistry symbol, not a quality rating.
Is NAD+ vitamin B3?
No. NAD is a coenzyme that the body can synthesise using precursors that include forms of vitamin B3 and tryptophan. A precursor and the final coenzyme are not the same thing.
Does NAD+ increase collagen?
NAD-related pathways are relevant to fibroblast biology in laboratory research, but this does not prove that an NAD-targeted intervention increases collagen or tightens skin in people. Direct clinical evidence for visible cosmetic outcomes is limited.
Can an NAD blood test show cellular ageing?
A blood measurement may provide information about a sample at a particular time, but it does not necessarily reflect free NAD+/NADH ratios inside specific tissues or mitochondria. It is not a stand-alone measure of biological or skin age.
Are NAD+ supplements or treatments proven to reverse ageing?
No intervention has been established as a general treatment that reverses human ageing. Some studies show changes in NAD-related biomarkers, while consistent, meaningful clinical benefits remain uncertain.
Why discuss NAD in a skin clinic article?
NAD biology is a useful way to understand cellular energy and repair pathways. For aesthetic medicine, the responsible message is that skin ageing is multi-layered and cannot be reduced to one molecule or one treatment.
References and Further Reading
Medical, regulatory and results disclaimer This article provides general educational information and does not replace medical, pharmaceutical, regulatory or legal advice. It does not promote or recommend an NAD, NAD+, NADH or NMN product. Evidence and Australian regulatory requirements may change. Suitability and risks of any health service or therapeutic good require individual assessment by appropriately qualified professionals. |