Barrier Renewal & Brightening cream
Niacinamide is having a moment, and the percentages keep climbing. So is a 10% serum really twice as good as a 5% cream? Not according to the research.
If you are weighing up 5% vs 10% niacinamide, start with 5% unless you already know your skin is comfortable with the ingredient. Five per cent is the strength used in 12-week, double-blind, split-face research on the look of ageing skin (Bissett et al., 2004; Bissett et al., 2005). A safety review found that niacinamide at up to 10% did not sting in clinical testing, but the irritation tests it summarises went only as high as 5% (Cosmetic Ingredient Review, 2005). In the research we reviewed, no clinical study showed 10% working better than 5%.
Key takeaways
In this guide
So a higher number is not automatically better. Bysachè makes both, the 5% Niacinamide & 1% Bifida Ferment Cream and the 10% Niacinamide Serum, and the real difference between them is as much about format as percentage.
Niacinamide is a form of vitamin B3 (Bissett et al., 2005). Its appeal is breadth rather than drama.
For more on the science, read our guide to niacinamide and the skin barrier.
The clinical studies we reviewed used 2% to 5%, often in split-face designs, where each side of the face gets a different product.
In Japan, 50 people used a 2% niacinamide moisturiser for 4 weeks and 50 used a placebo. The niacinamide group’s sebum excretion rate, a measure of how quickly skin produces oil, was significantly lower at 2 and 4 weeks. In a 6-week split-face study of 30 people in the US, oil on the skin’s surface fell significantly, though the excretion rate did not (Draelos et al., 2006).
Thirty healthy Japanese women applied a 4% niacinamide cosmetic to eye-area lines on one side of the face for 8 weeks, and a niacinamide-free version to the other. The niacinamide side showed marked or moderate improvement in 64% of participants; one person stopped because of minimal irritation (Kawada et al., 2008). A 2021 review also describes a split-face trial in which 4% niacinamide reduced the look of pores and unevenness after 8 weeks (Boo, 2021).
Two 12-week papers from the same research group used 5%. In the first, 50 women aged 40 to 60 used a 5% niacinamide moisturiser on one side of the face and the same moisturiser without it on the other. The niacinamide side improved in fine lines, spots, texture, red blotchiness and sallowness (a yellowish cast), and it was well tolerated (Bissett et al., 2004). The second paper, which describes the same design (50 women, 5% twice daily for 12 weeks), adds that elasticity, measured with an instrument, also improved (Bissett et al., 2005).
Strength did matter at the lower end. In a comparison described in a 2021 review, a 5% moisturiser reduced the look of spots more than a plain moisturiser after 4 or 8 weeks, while a 2% version showed no statistically significant effect (Boo, 2021).
Here the evidence thins. Clinical testing summarised by the Cosmetic Ingredient Review panel found no stinging with niacinamide at up to 10%, but its use tests and 21-day irritation test went only as high as 5% (Cosmetic Ingredient Review, 2005). A 2021 review describes niacinamide as well tolerated at the concentrations normally used, which it gives as below 5% (Boo, 2021).
Nor is there clear evidence that more does more. In a 2025 laboratory study on samples of the skin’s outermost layer, niacinamide changed how the samples took up water. The researchers tested 2.5%, 5%, 10% and 20%, and report that the effects appeared independent of dose (Sjöberg et al., 2025). That is a lab finding, not a result on living skin, but it fits the wider picture: we found no clinical study comparing 5% and 10% niacinamide head to head.
| What to weigh | 5% | 10% |
|---|---|---|
| Clinical research | Used in 12-week research on the look of ageing skin | No head-to-head trial against 5% in the research we reviewed |
| Tolerability testing | No irritation in use tests or a 21-day irritation test | No stinging in clinical testing; irritation tests went only to 5% |
| Does more do more? | Reduced the look of spots where 2% did not, in one comparison | Lab data suggests effects may not rise with dose |
| Bysachè format | Cream with bifida ferment lysate, shea butter and sunflower oil; contains parfum | Water-light serum with pineapple extract; contains orange peel, ylang-ylang and rosemary leaf oils |
Product spotlight · Barrier Renewal & Brightening
5% Niacinamide & 1% Bifida Ferment Cream
The research strength in a cream you can wear as the last step of your routine, morning or evening. Niacinamide meets bifida ferment lysate, shea butter, sunflower oil and vitamin E for a soft, cushioned finish. Contains parfum, so patch test if your skin is fragrance-sensitive.
Product spotlight · Improves Skin Tone & Radiance
A water-light serum that sets 10% niacinamide in a base with pineapple extract and glycerin, and no zinc. It layers easily under moisturiser and is recommended for evening use. Contains orange peel, ylang-ylang and rosemary leaf oils.
Both formulas contain fragrance ingredients (see the table). If your skin tends to react to fragrance or essential oils, patch test first.
An easy evening niacinamide routine
If you also use vitamin C, such as our Vitamin C 20% Brightening Serum, see how to use niacinamide and vitamin C together. For a gentler routine overall, see our skin barrier guide, and for the right order of every step, our skincare layering guide.
Not necessarily, but it has less testing behind it. Niacinamide did not sting at up to 10% in clinical testing, while the irritation tests went up to 5% (Cosmetic Ingredient Review, 2005). Reactions also vary from person to person (Boo, 2021), so patch test.
We found no evidence that 10% niacinamide works faster or better than 5%. In the lab study above, effects did not appear to rise between 2.5% and 20%. Consistency is the part you control.
It is one of the better-studied options. In two trials, a 2% niacinamide moisturiser lowered measures of facial oil (Draelos et al., 2006). If your skin leans oily, a lighter serum texture may feel more comfortable than a cream.
You can, but most routines only need one. If you use both, apply the serum first and the cream over it, and introduce them one at a time.
For most people weighing 5% vs 10% niacinamide, 5% is the sensible place to start: it has direct clinical research and more tolerability testing behind it. Choose 10% if your skin already knows niacinamide and you prefer a light serum. Either way, the evidence does not show that doubling the percentage doubles the result. Pick the texture you will enjoy every day, patch test, and give it time.
Ready to choose? Start with the 5% Niacinamide & 1% Bifida Ferment Cream, or step up to the 10% Niacinamide Serum if your skin already loves niacinamide.
The Bysachè approach
We prioritise quality over quantity. Our line is intentionally limited, so every product has to earn its place in a simple, effective routine.
Barrier Renewal & Brightening cream
Overnight Renewal & Hydration