Niacinamide: What the Evidence Actually Supports
Niacinamide is among the most extensively evidenced actives in cosmetic science — and one of the most misunderstood. What it does, at what concentrations, and which cautions are real versus internet folklore.
In short: niacinamide is vitamin B3 and a precursor to NAD+, the coenzyme central to cellular energy metabolism. Topically it is associated with improved barrier function, reduced appearance of pores, better sebum regulation and more even-looking tone. Most studied benefits appear between 2% and 5%; higher concentrations increase irritation risk without clear additional benefit.
What niacinamide is
INCI: Niacinamide. Also called nicotinamide. It is the amide form of vitamin B3, water-soluble, stable across a wide pH range, and small enough to penetrate the stratum corneum well — an unusually convenient combination for a cosmetic active.
Its relevance to mitochondrial skincare is that it is a precursor to NAD+, the coenzyme that sits at the centre of cellular energy metabolism. NAD+ availability declines with age, and that decline is one of the better-documented threads in longevity biology.
- INCI name
- Niacinamide
- Also known as
- Nicotinamide, vitamin B3
- Solubility
- Water soluble
- Stable pH range
- Approximately 5 to 7
- Typical use level
- 2–5%
- Cosmetic functions
- Skin conditioning; smoothing
- Evidence maturity
- Strong — extensive published human data
What the evidence supports
| Outcome | Evidence strength | Typical study concentration |
|---|---|---|
| Barrier function and transepidermal water loss | Strong | 2–5% |
| Appearance of pore size | Good | 2–5% |
| Sebum regulation | Good | 2–4% |
| Evenness of tone and appearance of pigmentation | Good | 4–5% |
| Appearance of fine lines | Moderate | 4–5% |
| Redness and blotchiness appearance | Moderate | 2–4% |
Why more is not better
Niacinamide is widely sold at 10% and occasionally higher. The published benefits cluster well below that, and the practical consequence of pushing concentration up is a higher rate of flushing, stinging and irritation — particularly on reactive skin.
If a 10% product has caused you problems, that is a common experience and does not mean niacinamide doesn't suit you. It usually means the concentration was higher than you needed.
- “Niacinamide cancels out vitamin C.” This derives from mid-twentieth-century work on heated solutions forming niacin. It does not reflect how modern formulations behave at room temperature on skin. Using both is fine.
- “Higher percentage means a better product.” The evidence clusters at 2–5%.
- “It shrinks pores.” Pore size is largely structural. What changes is appearance — which is what the studies measure and what claims should say.
- “It exfoliates.” It does not. It is not an acid and has no exfoliating action.
How to use it
Niacinamide is one of the easiest actives to place in a routine. It is stable, pH-flexible, and compatible with essentially everything — retinoids, acids, peptides, vitamin C, and methylene blue. Serum step, morning or evening or both.
If you are new to it and have reactive skin, start with a lower concentration and use it every other day for the first week.
Frequently asked questions
What percentage of niacinamide should I use?
Between 2% and 5% for most people. That is where the published benefits cluster. Higher concentrations raise irritation risk without clear additional benefit.
Can I use niacinamide with vitamin C?
Yes. The idea that they cancel each other out comes from old research on heated solutions and does not reflect how modern formulations behave on skin at room temperature.
Can I use niacinamide with retinol?
Yes, and it is a common pairing. Niacinamide's barrier-supporting effect can make a retinoid easier to tolerate.
Does niacinamide help with acne?
It has evidence for sebum regulation and for the appearance of redness, which is why it appears in products aimed at blemish-prone skin. It is a cosmetic ingredient, not a treatment for acne as a medical condition — for persistent or severe acne, see a GP or dermatologist.
Why does niacinamide make me flush?
Flushing is more associated with niacin than niacinamide, and with higher concentrations. If a product causes it, try a lower percentage.
Formulated on what the evidence supports
One serum. Nine actives. Methylene blue at cosmetic concentration. Made in London.
Shop the serumThis page is general information about cosmetic ingredients and is not medical advice.