Niacinamide 10% — Is That Too Much? Optimal Concentration, Myths and Facts

Niacinamide (nicotinamide, the amide of nicotinic acid) is one of the most widely used forms of vitamin B3 in cosmetics. You'll find it in products ranging from The Ordinary to Sulwhasoo, at concentrations from 2 to 20%. But the marketing logic of "more = better" doesn't hold up in dermatology — and niacinamide is a perfect example. Let's take a closer look at what the research actually says about the optimal concentration.

How does niacinamide work on the skin?

Niacinamide is a precursor of the coenzyme NAD+ (nicotinamide adenine dinucleotide), which is involved in more than 400 enzymatic reactions in skin cells. Its documented effects include:

• Strengthening the skin barrier — it stimulates the synthesis of ceramides (especially ceramide NP and AP), cholesterol and free fatty acids in the stratum corneum
• Reducing discolouration — it inhibits the transfer of melanosomes from melanocytes to keratinocytes without blocking melanin production itself (unlike hydroquinone)
• Regulating sebum — it reduces oil production by 15–25% after 4 weeks of use
• Anti-inflammatory action — it inhibits mast cell degranulation and the production of prostaglandin E2
• Improving texture — it stimulates the production of collagen and elastin in the dermis

The Draelos study (2006) — the gold standard

The most important study on the optimal concentration of niacinamide was conducted by the team of Dr Zoe Draelos and published in Dermatologic Therapy in 2006. This randomised, double-blind study involving 50 Caucasian women compared a cream with 2% niacinamide to a cream with 5% niacinamide, used over 12 weeks.

The results:

• 5% niacinamide — a statistically significant improvement in hyperpigmentation (p < 0.05), skin elasticity and a reduction in redness
• 2% niacinamide — a significant improvement in hydration and skin texture, but a weaker effect on discolouration
• Tolerance of both concentrations — excellent, with no significant adverse effects

The key takeaway: 5% is the optimal concentration for most skincare goals. It delivers the full spectrum of benefits with minimal risk of irritation.

10% niacinamide — does it offer more benefits?

The short answer: no. The longer answer: a 2010 study published in the Indian Journal of Dermatology, Venereology and Leprology compared concentrations of 2%, 4% and 5% niacinamide in the treatment of acne vulgaris. The difference between 4% and 5% was minimal, which suggests a plateau effect — above a certain concentration, the additional niacinamide molecules find no free receptors or enzymes to react with.

What's more, a 10% concentration comes with specific risks:

Irritation and redness

At high concentrations, niacinamide can undergo non-enzymatic hydrolysis to nicotinic acid (niacin) under the influence of heat, moisture and the skin's acidic pH. Nicotinic acid triggers a vasomotor reaction — so-called flushing — manifesting as sudden redness, a sensation of warmth and a burning feeling on the face. The effect is temporary (15–30 min) but unpleasant, and it can intensify erythema in people with rosacea.

Formula destabilisation

At concentrations above 5%, niacinamide tends to crystallise in aqueous solutions, which can lead to uneven distribution of the ingredient throughout the product. Manufacturers get around this by adding solvents (e.g. propanediol), which increases the risk of irritation in people with sensitive skin.

The myth about niacinamide reacting with vitamin C

One of the most persistent myths in skincare claims that niacinamide and L-ascorbic acid (vitamin C) cannot be used together because they neutralise each other. Where does this myth come from?

It originates from a study from 1963 (!) in which pure solutions of niacinamide and ascorbic acid were mixed in a test tube at a temperature above 70°C. Under those extreme conditions, a niacinamide–ascorbate complex formed that did indeed reduce the activity of both ingredients. However:

• Human skin has a temperature of 32–34°C — the reaction essentially does not occur
• The pH of modern cosmetic formulas is buffered and stable
• The concentrations of both ingredients in cosmetics are too low to trigger a meaningful chemical reaction

A 2020 study (Journal of Cosmetic Dermatology) confirmed that using 5% niacinamide and 15% vitamin C together does not reduce the effectiveness of either ingredient and does not increase the risk of irritation. You can safely combine the two in a single routine.

Forms of vitamin B3 — a comparison

Niacinamide is not the only form of vitamin B3 used in cosmetics. It's worth knowing the differences:

Practical recommendations

Based on the available scientific data, we recommend:

• Normal skin, prevention — niacinamide 2–3% in a moisturiser
• Discolouration, uneven skin tone — 5% niacinamide in a serum, used daily for a minimum of 8 weeks
• Oily skin, enlarged pores — 4–5% niacinamide in a lightweight gel or essence
• 10% and above — not recommended. No evidence of additional benefits, and an increased risk of irritation

If you already have a 10% niacinamide serum and tolerate it well — there's no need to throw it away. But for your next purchase, consider a product with a 5% concentration: the same effect, less risk, a lower price.