NAD+ and Skin: The Cellular Energy Molecule That Repairs Your Barrier

What is NAD+?

NAD+ stands for nicotinamide adenine dinucleotide — a coenzyme present in every cell of the body. It exists in two forms: NAD+ (the oxidised form) and NADH (the reduced form). The ratio between these forms is critical to cellular health.

NAD+ is central to two essential cellular processes: energy metabolism and DNA repair. Without adequate NAD+, cells cannot efficiently convert nutrients into energy, cannot repair DNA damage, and cannot maintain normal function. In the skin, this translates directly to the barrier’s ability to repair itself after damage.

What does NAD+ do for skin?

1. Powers cellular energy production

Skin cells need energy to produce ceramides, synthesise collagen, repair DNA damage, and regulate inflammation. NAD+ is a critical intermediate in the process that generates this energy. When NAD+ levels fall, all these processes slow down.

2. Activates sirtuins — longevity proteins

Sirtuins are proteins that regulate cellular ageing, inflammation, and stress responses. They require NAD+ to function. As NAD+ declines with age, sirtuin activity falls — contributing to accelerated skin ageing.

3. Supports DNA repair

UV radiation and pollution cause constant DNA damage in skin cells. The PARP enzymes responsible for repairing this damage are major consumers of NAD+. Adequate NAD+ ensures efficient DNA repair, reducing photoageing.

4. Reduces oxidative stress

NAD+ supports the regeneration of glutathione — the skin’s most important antioxidant — and helps neutralise reactive oxygen species generated by UV exposure and pollution.

5. Regulates inflammation

Through its role in sirtuin activation, NAD+ helps maintain a balanced inflammatory response. Chronically low NAD+ is associated with increased baseline inflammation — a key driver of barrier dysfunction.

Why NAD+ declines with age

NAD+ levels in human tissue decline by approximately 50% between the ages of 40 and 60 — with the decline beginning from the mid-20s. Several factors drive this:

• Increased PARP activity — More DNA damage with age means more NAD+ consumed by repair enzymes.
• Reduced biosynthesis — The enzymes that synthesise NAD+ become less efficient with age.
• CD38 enzyme activity — CD38, which degrades NAD+, becomes more active with age and chronic inflammation.
• Poor diet and lifestyle — Low intake of NAD+ precursors, poor sleep, excess alcohol, and sedentary behaviour accelerate decline.

Topical NAD+ in skincare

A growing number of skincare products now include NAD+ or its precursors. The practical question is whether topical application is effective — NAD+ molecules are relatively large and may struggle to penetrate deeply.

Early studies show improvements in skin hydration, reduced oxidative stress markers, and some anti-ageing effects — but larger controlled trials are needed.

Oral NAD+ precursors: NMN and NR

Precursor	Full name	Research status
NMN	Nicotinamide mononucleotide	Multiple human trials — promising results
NR	Nicotinamide riboside	Most human trial data — well-established safety
Niacinamide	Nicotinamide (vitamin B3)	Decades of human data — most accessible

Human trials with NR and NMN consistently show that oral supplementation raises blood NAD+ levels by 40–60%. Whether this translates to meaningful skin improvements requires more dedicated research.

NAD+ vs niacinamide — what’s the difference?

Niacinamide is a precursor that your body converts into NAD+. They’re related but not the same thing. Niacinamide also has direct effects on skin — reducing inflammation, regulating sebum, strengthening the barrier — independent of its role as an NAD+ precursor.

Think of niacinamide as the well-established foundation and dedicated NAD+ ingredients as the next step for those focused on cellular longevity.

How to use NAD+ for skin health

Step 1 — Start with niacinamide

A 5% niacinamide serum used daily is the most accessible, evidence-based way to support skin NAD+ levels while simultaneously improving barrier function.

Step 2 — Consider a dedicated NAD+ serum

Look for serums that specifically list NAD+ or NADH as active ingredients. Apply after cleansing and before moisturiser, morning or evening.

Step 3 — Support from within

For a comprehensive approach, oral NR or NMN supplementation addresses NAD+ depletion systemically — particularly relevant for those over 40.

Approach	Method	Evidence level
Topical niacinamide	5% serum daily	Strong — multiple clinical trials
Topical NAD+	NAD+ serum AM or PM	Emerging — promising early data
Oral NR/NMN	250–500mg daily	Moderate — raises NAD+ levels