5% Niacinamide: What the Research Really Says

Key takeaways

• Niacinamide (vitamin B3) is one of the best-studied actives: skin barrier, sebum, dark spots, redness.
• Reference studies use 2 to 5%; beyond that, the benefit is not proven and the risk of discomfort rises.
• It combines easily, including with vitamin C. Allow several weeks to see its effects.

Few actives have become popular as quickly as niacinamide. Found in a large share of Korean serums, it is often sold on the strength of one number: 5%. But that percentage deserves some context.

What does niacinamide do for the skin?

It is a form of vitamin B3, associated with several documented effects:

• the skin barrier: it stimulates the skin's own ceramide production and reduces water loss;
• sebum: at 2%, it reduced facial sebum production within a few weeks in a clinical study;
• dark spots: it limits the transfer of pigment to surface cells, gradually fading dark spots;
• signs of ageing: at 5%, it improved the look of fine lines, spots and skin tone over twelve weeks;
• diffuse redness, linked to a stronger barrier.

Its effects build up over several weeks of regular use, rarely within a few days.

Where does the 5% figure come from?

This concentration comes from the reference studies on dark spots, sebum and skin ageing, generally carried out at concentrations between 2% and 5%. Beyond that, additional benefits are not clearly demonstrated, while the risk of discomfort increases for sensitive skin: temporary redness, tingling, a feeling of warmth.

In practice:

• 2 to 5%: the best-documented range, suitable for most skin types and daily use;
• 10% and above: targeted formulas, often for dark spots, to introduce gradually and to avoid if your skin is reactive.

Tolerance depends on the rest of the formula

Niacinamide is known to be well tolerated, but how it feels depends a lot on the ingredients around it: too much alcohol or acid in the same formula can cause tingling that is not caused by niacinamide itself, but is often wrongly blamed on it.

What to pair it with, and how to avoid overload

Niacinamide works well with hyaluronic acid, ceramides, centella or daily sunscreen. The idea that it should never be combined with vitamin C comes from old studies carried out at high temperatures; in today's formulas, the combination is common and well tolerated by most skin types.

On the other hand, it does not need to be stacked with several other actives targeting the same concern (several dark spot serums, for example), which only adds the risk of irritation without extra benefit.

Which format to choose

• Serum, for daily use, such as the Peach 70 Niacin Serum by Anua.
• Gel cream, for combination to oily skin, such as the Centella 5% Niacinamide Radiance Gel Cream by Haruharu Wonder.
• Soaked pads, for a quick morning step, such as the No.5 Vitamin Niacinamide Concentrated Pad by Numbuzin.

The percentage shown on packaging is useful information, but never enough on its own to judge how well a product really works.

Frequently asked questions

Can I use niacinamide morning and evening?

Yes. It is stable and does not make the skin more sensitive to the sun.

Are niacinamide and retinol compatible?

Yes. Niacinamide can even help the skin tolerate retinol better, thanks to its effect on the skin barrier.

Why does my skin turn red after a niacinamide serum?

Often because of a high concentration or other ingredients in the formula. Try a formula at 5% or less, every other day at first.

Read also: Korean vs Western vitamin C · Damaged skin barrier: how to repair it

Sources

• Hakozaki T et al. The effect of niacinamide on reducing cutaneous pigmentation and suppression of melanosome transfer. Br J Dermatol, 2002. doi:10.1046/j.1365-2133.2002.04834.x
• Bissett DL et al. Niacinamide: A B vitamin that improves aging facial skin appearance. Dermatol Surg, 2005. doi:10.1111/j.1524-4725.2005.31732
• Draelos ZD et al. The effect of 2% niacinamide on facial sebum production. J Cosmet Laser Ther, 2006. doi:10.1080/14764170600717704
• Tanno O et al. Nicotinamide increases biosynthesis of ceramides as well as other stratum corneum lipids. Br J Dermatol, 2000. doi:10.1111/j.1365-2133.2000.03705.x