Niacinamide explained: what it does, how much you need, and what to pair it with
Niacinamide, also called nicotinamide, is a form of vitamin B3. In twenty years it has gone from an obscure moisturizer ingredient to one of the most common actives on US and Asian labels alike. It has better evidence behind it than most trendy ingredients, and it is unusually easy to tolerate. It is also routinely oversold, and sold at strengths far above what the research used.
- Controlled trials have used niacinamide at around 2% to 5%, showing improvements in redness, blotchiness, uneven pigmentation, texture and fine lines over 8 to 12 weeks.
- It supports the skin barrier and is generally well tolerated, including by many people with sensitive skin.
- Higher is not necessarily better: 10% and above is more likely to cause irritation in some people, with no clear extra benefit in published trials.
- The warning not to combine niacinamide with vitamin C comes from old chemistry experiments, not from modern formulas.
What niacinamide is
Inside cells, niacinamide is a building block of NAD and NADP, coenzymes involved in energy metabolism and DNA repair. In skincare it is a stable, water-soluble white powder that dissolves easily into serums and moisturizers and is not sensitive to light or air in the way vitamin C or retinol are. That stability is one reason formulators like it: it survives shipping, heat and long shelf lives better than most actives.
It should not be confused with niacin (nicotinic acid), the form of vitamin B3 that, taken in high doses by mouth, causes the well-known "niacin flush". Topical niacinamide does not typically cause that kind of flushing.
What the research shows
The best-known studies were carried out by researchers at Procter & Gamble, which uses niacinamide in its own products, so they deserve a reading with that in mind. They were, however, randomized and controlled.
- Aging signs and tone. In a split-face trial published by Bissett and colleagues in Dermatologic Surgery (2005), 50 women applied 5% niacinamide to one side of the face and a plain moisturizer to the other, twice a day for 12 weeks. The niacinamide side showed improvement in fine lines and wrinkles, hyperpigmented spots, red blotchiness and sallowness. An earlier trial by the same group (2004) reported similar results.
- Pigmentation. Hakozaki and colleagues (2002, British Journal of Dermatology) showed that niacinamide reduced the transfer of pigment from melanocytes to surrounding skin cells in laboratory models, and reduced hyperpigmentation in clinical tests. It is not as strong as prescription treatments for melasma, but it is one of the gentlest options for uneven tone.
- Barrier function. Laboratory and small clinical studies have found that niacinamide increases the production of ceramides and other barrier lipids in the epidermis and reduces water loss through the skin. This is the basis for its use in barrier and "sensitive skin" moisturizers.
- Acne and oiliness. Several small trials have tested niacinamide gels for mild acne and for reducing the look of oiliness, with modest results. It is a reasonable supporting ingredient, not a replacement for benzoyl peroxide, salicylic acid or adapalene.
Oral nicotinamide has been studied by dermatologists for a different purpose: reducing new non-melanoma skin cancers in high-risk patients. That is a medical use, at medical doses, decided with a doctor. It says nothing about what a serum does.
How much do you need?
Most of the controlled evidence uses 2% to 5%. Many popular serums now advertise 10%, 15% or even 20%. There is little published evidence that these higher strengths work better, and dermatologists report that they are more likely to cause stinging, redness or a gritty texture on the skin, particularly in people with sensitive skin or rosacea. A moisturizer that lists niacinamide in the top third of its ingredients is often enough.
| Strength | Typical product | Who it suits |
|---|---|---|
| 2–5% | Moisturizers, light serums | Most skin types, including sensitive; the range used in trials |
| 10% | Dedicated serums | Oily skin that tolerates it; patch test first |
| Above 10% | "High-strength" serums | Little added evidence; higher chance of irritation |
The vitamin C myth
You may have read that niacinamide and vitamin C (ascorbic acid) cancel each other out, or that together they form niacin and make you flush. This idea goes back to laboratory experiments from the mid-twentieth century in which pure niacinamide and pure ascorbic acid were heated together for long periods. Under those conditions they react. In a finished product at room temperature, or layered on the skin for a few minutes, the conversion is very slow. Dermatologists now generally say the two can be used in the same routine. If your skin is sensitive, applying vitamin C in the morning and niacinamide in the evening is a simple way to avoid any doubt, and avoids layering two products at once.
What it pairs well with
- Hyaluronic acid and glycerin. Both are humectants; together they make a simple hydrating base. See our decoded hyaluronic acid serum.
- Retinoids. Niacinamide's barrier support can make retinoid irritation easier to live with; many retinoid moisturizers include it. See retinoids explained.
- Sunscreen. Several sunscreens include niacinamide in the base, which is convenient in the morning.
- Exfoliating acids. Fine together for most people, though acids at a low pH may make any second product sting more. Our guide to combining active ingredients has the details.
How to use it
- Pick one product. A moisturizer or a serum, not both at high strength.
- Apply once or twice a day after cleansing, before or as your moisturizer.
- Give it 8 to 12 weeks. That is the length of the trials. Redness may calm sooner; tone and texture take longer.
- Keep sunscreen in the morning. Niacinamide does not protect against UV, and uneven pigmentation returns quickly with sun exposure.
Who should be careful
Niacinamide is among the least problematic actives, but no ingredient suits everybody. People who have reacted to "niacinamide serums" have often been using high strengths, or products with fragrance or several other actives. If you have rosacea, start with a low-strength moisturizer. If redness, itching or small bumps appear and persist, stop and check the rest of the formula; the irritant may not be the niacinamide.
Sources
- Bissett D.L. et al., "Niacinamide: a B vitamin that improves aging facial skin appearance", Dermatologic Surgery, 2005.
- Bissett D.L. et al., "Topical niacinamide reduces yellowing, wrinkling, red blotchiness, and hyperpigmented spots in aging facial skin", International Journal of Cosmetic Science, 2004.
- Hakozaki T. et al., "The effect of niacinamide on reducing cutaneous pigmentation and suppression of melanosome transfer", British Journal of Dermatology, 2002.
- Tanno O. et al., "Nicotinamide increases biosynthesis of ceramides as well as other stratum corneum lipids to improve the epidermal permeability barrier", British Journal of Dermatology, 2000.
- Chen A.C. et al., "A phase 3 randomized trial of nicotinamide for skin-cancer chemoprevention", New England Journal of Medicine, 2015.
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