High-Percentage Niacinamide: Is 20% Better Than 5%?

No published trial compares 20 percent niacinamide against 5 percent on the same faces. Nearly all of the clinical evidence sits between 2 and 5 percent. The one controlled trial above that range used a 10 percent nicotinamide combination product. A higher number raises how much sits on your skin, not how much gets through it. Concentration and delivery are separate problems, and only one of them is printed on the box.

Is 20 percent niacinamide better than 5 percent?

Nobody has shown that it is. The studies that built niacinamide's reputation used 5 percent or less. None tested a higher arm alongside.

Bissett, Oblong and Berge ran 5 percent niacinamide against its own vehicle in Dermatologic Surgery in 2005. Fifty women applied one to each half of the face for 12 weeks. The niacinamide side showed measured improvement in fine lines, spots, red blotchiness and yellowing. The same group ran the split-face design a year earlier, also at 5 percent. That report sits in the International Journal of Cosmetic Science.

Hakozaki and colleagues published the pigment work in the British Journal of Dermatology in 2002. In coculture, niacinamide inhibited melanosome transfer by 35 to 68 percent. The clinical arm used a 5 percent moisturizer in 18 people with hyperpigmentation. A second trial enrolled 120 people with facial tanning. Each was assigned two of three treatments: vehicle, sunscreen, and 2 percent niacinamide with sunscreen.

Niacinamide's effects are concentration dependent. Wohlrab and Kreft say so in Skin Pharmacology and Physiology. They add a condition most marketing drops: sufficient bioavailability. Which effect appears depends on the concentration used. Above 5 percent, the record on human faces thins to one combination-product trial.

What concentration of niacinamide has actually been studied?

Here is the published range, with the design of each trial. None of these studies tested a re:tones product.

Concentration	Study	Design	What was measured
2%	Draelos 2006	100 Japanese subjects, placebo controlled, 4 weeks	Sebum excretion rate
2% with sunscreen	Hakozaki 2002	120 subjects with facial tanning, each assigned two of three treatments	Facial pigmentation, skin lightness
4%	Navarrete-Solís 2011	27 melasma patients, split face against 4% hydroquinone, 8 weeks	Colorimetry, histology, side effect rate
4% gel	Shalita 1995	76 patients, double blind against 1% clindamycin gel, 8 weeks	Inflammatory acne lesion counts
5%	Bissett 2005	50 women, split face against vehicle, 12 weeks	Wrinkles, spots, red blotchiness, elasticity
Up to 10%	CIR Expert Panel 2005	Safety assessment, stinging and irritation testing	Tolerance, not efficacy
10% in a combination product	Barbosa 2024	50 women with facial melasma, randomized double blind against 4% hydroquinone, 60 days	mMASI, quality of life, colorimetric luminosity
20% and above	None found	No published human trial located	Nothing

The melasma trial is the useful one for anyone assuming a bigger number is the only lever. At 4 percent, colorimetry showed no statistical difference against 4 percent hydroquinone. Good to excellent improvement was seen in 44 percent of patients with niacinamide and 55 percent with hydroquinone. Side effects appeared in 18 percent of niacinamide sides and 29 percent of hydroquinone sides. That trial varied the active, not the concentration. Read melasma versus hyperpigmentation before you treat one as the other.

One controlled trial has gone above 5 percent on faces. Barbosa and colleagues ran 10 percent nicotinamide with magnesium ascorbyl phosphate 5 percent and hyaluronic acid 5 percent. Fifty women with facial melasma were randomized to it or to 4 percent hydroquinone for 60 days. Two did not complete. In the nicotinamide group mean mMASI fell 16 percent at day 14, 95% CI 8 to 24. At day 60 it fell 32 percent, 95% CI 23 to 41. The hydroquinone group fell 10 percent (7 to 24) and 43 percent (34 to 52). The trial found no statistically significant difference between the two arms at either timepoint. The authors call the combined product numerically inferior to hydroquinone overall. It is a three-active formula, so the 10 percent figure cannot be read alone.

Why a bigger number does not mean more in your skin

Niacinamide is water loving. Its log P is about minus 0.35. Abraham and colleagues report that figure in the International Journal of Pharmaceutics in 2025. The value is the problem. The stratum corneum is a lipid brick wall, and water loving molecules cross it poorly.

Donor pH changed how much crossed in one laboratory setup. A 2026 paper in Scientific Reports measured that one variable. Sjöberg and colleagues ran Franz cell diffusion on excised human skin and on reconstructed epidermis. The donor was a plain buffer holding 5 percent niacinamide, not a finished formula. A donor pH of 7.4 roughly doubled niacinamide permeation against a donor pH of 5.0. The effect was reversible and tracked changes in the skin's lipid organization. The authors note that real applied volumes are much smaller, so translation is uncertain. The study varied pH only. It never varied concentration, so it ranks nothing against the number on the label.

The barrier is the reason delivery gets studied at all. Abraham and colleagues also tested powder-filled cavity microneedles loaded with niacinamide against a serum control. That was laboratory work on excised skin, not a face. We will not report a laboratory result as if it were about our product. Those needles are not a home pen, and no re:tones product was tested. What the paper does establish is the starting problem. A log P of minus 0.35 is why the stratum corneum is the limiting step here.

Cells respond to niacinamide at low concentrations in culture. Tanno and colleagues bathed cultured keratinocytes at 1 to 30 micromolar. Ceramide synthesis rose 4.1 to 5.5 fold over control by day six. That paper ran in the British Journal of Dermatology in 2000. A culture dish is not a face. A molar bath concentration at the cell does not convert to a weight percentage on a label. The two units are not comparable.

Doubling the percentage of a molecule that cannot get in mostly doubles what dries on the surface. This is the same argument as why your serum is not absorbing. For the routes in detail, read transdermal delivery explained.

Does niacinamide cause flushing?

No. Flushing belongs to the other form of vitamin B3. Niacin, also called nicotinic acid, triggers it. Niacinamide, also called nicotinamide, is the amide form.

The mechanism is specific. Nicotinic acid flushing runs through the receptor GPR109A. Benyó and colleagues showed epidermal Langerhans cells are the cells that carry it. Those cells make the vasodilatory prostanoids. Deplete them and the flush stops. The work ran in Molecular Pharmacology. A 2024 review in Archives of Biochemistry and Biophysics traces the same cascade to prostaglandin D2.

Niacinamide does not activate that receptor. A mouse study in Cardiovascular Research used nicotinamide as its GPR109A-negative comparator. That is animal work, cited here only for the receptor. No receptor, no flush.

One caveat is real and recent. The Scientific Reports team saw niacinamide convert to nicotinic acid on excised skin membranes during long diffusion runs. The amount was under 0.05 percent of the dose applied. Conversion was negligible within the first 24 hours. It became detectable only after prolonged exposure. The authors read it as a reason to weigh microbe driven conversion when judging topical niacinamide.

Redness after a niacinamide serum can come from something else in the bottle. Check the acids, the fragrance and the preservative system. Skincare actives explained covers the usual suspects.

How much niacinamide does skin tolerate?

Tolerance data runs out sooner than the marketing does. The Cosmetic Ingredient Review Expert Panel assessed niacinamide and niacin in 2005. The report ran in the International Journal of Toxicology. Three findings matter to anyone holding a high percentage bottle, ours included.

• Clinical testing produced no stinging sensation at concentrations up to 10 percent.
• Use tests produced no irritation at concentrations up to 5 percent.
• A 21-day cumulative irritation test at up to 5 percent produced no irritancy.

The panel also recorded the market of the day. Reported use concentrations ran from 0.0001 percent in night preparations to 3 percent in creams and lotions. Niacinamide was not a sensitizer and not a photosensitizer. The panel concluded both ingredients were safe as used.

Above 5 percent the human irritation record thins out. Above 10 percent the CIR report has only a guinea pig sensitization challenge, not human tolerance data. That is an absence of evidence, not evidence of harm. It is still a reason to patch test rather than assume. If your barrier is already unhappy, start with skin barrier repair and come back later.

What 21 percent is for, and what it is not

Our pore ampoule, 01 re:vive-B3, is niacinamide 21 percent, or 210,000 ppm. If that unit is new to you, what ppm means in skincare explains it in a minute.

We do not claim 21 outperforms 5. No trial supports that sentence, and we will not write it. Twenty one percent also sits above every concentration the CIR panel had human tolerance data for. No human irritation record exists at that level, for our ampoule or for any other. That is why the patch test in the next section is not optional. Here is what the number is actually doing.

• The vial is crimp sealed and you open it once. It meets air and fingers on that one occasion.
• The ampoule is formulated for use with the device. The re:tones Tap Pen releases it as the tip meets skin. That pairing has not been tested for granuloma risk, and we do not claim it is exempt.
• The rest of the formula is on the carton, not hidden behind the hero number. It runs Adenosine 0.04 percent, rh-Oligopeptide-1 and Sodium DNA.

The sealed medical glass is a consequence of the format, not a styling choice. The container has to be sterile and single integrity. It is filled, crimped and opened once. A pump meets air and fingers every day.

If pore appearance is your priority, how to minimize pores sets expectations before you buy anything. If tone is the priority, compare notes in niacinamide versus vitamin C and consider 02 re:clear-T instead.

Using a high percentage with a needle

Any needling session changes the risk profile of what you apply afterwards. Treat technique as seriously as ingredients.

Soltani-Arabshahi and colleagues reported three women with facial granulomas after microneedle therapy. The cases ran in JAMA Dermatology in 2014. Two women had a branded moisturizer applied during the treatment. Biopsies showed foreign body type granulomas. The authors note that products applied before needling can be tattooed into the dermis. Our own ampoule is dispensed at needle contact. No study has tested it against that risk, so read the warning as covering it too. The rules below are not a safety exemption for anything we sell.

Practical rules, and none of them are optional.

• Patch test the ampoule on your jaw before it ever meets a needle.
• Start at the shallowest setting and the lowest intensity. Go shallow before you go deep. The depth range is listed on the Tap Pen page.
• Do not apply other products during a session. Do not improvise with your shelf.
• Once a week is the cadence. More is not faster.
• Use a fresh sterile cartridge every session. Never reuse one.
• Stop if stinging, tightness or redness lasts. Ask a clinician when it does.

Skip the device entirely in any of these cases.

• Active acne, eczema or rosacea in the treatment area.
• An active cold sore anywhere on the face.
• A keloid history or a bleeding disorder.
• Recent oral isotretinoin.
• Pregnancy.

Never treat over moles or broken skin. Who should not microneedle and microneedling side effects go through the full list. Ask a clinician when a condition is on it.

The Tap Pen does not diagnose, treat, cure or prevent any disease. Aftercare is covered in microneedling aftercare.

Frequently asked questions

Can I use 20 percent niacinamide every day?

Daily use at a high percentage has not been studied the way 5 percent has. We will not invent a cadence the evidence does not support. Patch test first, then follow the directions on the product you own. Stop if you get stinging, tightness or redness that lasts. Paired with the Tap Pen, the cadence is once a week.

Does niacinamide need a low pH to work?

No. Niacinamide carries no acid requirement of its own. One laboratory study is worth naming. In Franz cells on excised skin, a buffer at pH 7.4 roughly doubled permeation against pH 5.0. That result is in Scientific Reports. The authors note that translating it to real applied volumes is uncertain. The missing acid requirement is one reason niacinamide sits easily in routines that already sting.

Does niacinamide turn into niacin in the bottle?

Conversion is documented, but slowly and on excised skin membranes rather than in a sealed vial. The Scientific Reports team found the conversion negligible within 24 hours. It became detectable only after prolonged exposure. The route was microbial growth on the skin membrane during long diffusion runs. Adding 15 mM sodium azide to the donor and receptor solutions suppressed it.

Is more niacinamide better for pores?

Not on the published record. The sebum work by Draelos and colleagues used 2 percent. Sebum excretion rate fell in the Japanese arm at two and four weeks. Nobody has run 20 percent against 2 percent on sebum. Pore size is structural and does not track a percentage.

Can I use niacinamide with vitamin C?

One trial above did test the pair. Barbosa combined 10 percent nicotinamide with magnesium ascorbyl phosphate 5 percent, a vitamin C derivative. Mean mMASI fell 32 percent at day 60. That is a single combination product, so it settles little. Nothing in it suggests either ingredient disables the other. Hakozaki found niacinamide works on melanosome transfer, not on tyrosinase. If your skin objects, separate them by time of day. How to layer serums covers the order to use.

How long before niacinamide does anything?

The published endpoints in these trials read out between two and twelve weeks. Barbosa measured mMASI at fourteen days. Hakozaki measured pigment change at four weeks. Bissett ran twelve. Draelos measured a sebum change at two. How long until skincare works explains why skin cell turnover sets the floor.

Is niacinamide safe to apply right after microneedling?

Follow the device instructions and do not improvise. Two of the three granuloma cases in JAMA Dermatology involved microinjection of the same branded product during treatment. Do not apply other products during a session. Our ampoule is dispensed during the session and has not been tested against that risk. Do not improvise on skin that has just been treated. Hold off on acids, retinoids and fragrance until your skin looks normal again.

What does 210,000 ppm mean on the carton?

It is the same figure as 21 percent, written in parts per million. One percent is 10,000 ppm. Cartons use ppm when a percentage gets hard to read. Acetyl Hexapeptide-8 at 500 ppm is one example. Our ppm guide has the conversions.

Keep reading

• The niacinamide guide, for what the molecule does before any device is involved.
• Ampoule versus serum, for why the format is not just a smaller bottle.
• What is microneedling, for the mechanism behind the channel.
• Nano-needling versus microneedling, for where an 8 micron tip sits.
• The ampoule finder asks six questions and sets your depth.

Sources

• Bissett DL, Oblong JE, Berge CA. Niacinamide: a B vitamin that improves aging facial skin appearance. Dermatol Surg. 2005;31(7 Pt 2):860-865. PubMed
• Bissett DL, Miyamoto K, Sun P, Li J, Berge CA. Topical niacinamide reduces yellowing, wrinkling, red blotchiness, and hyperpigmented spots in aging facial skin. Int J Cosmet Sci. 2004;26(5):231-238. PubMed
• Hakozaki T, Minwalla L, Zhuang J, et al. The effect of niacinamide on reducing cutaneous pigmentation and suppression of melanosome transfer. Br J Dermatol. 2002;147(1):20-31. PubMed
• Draelos ZD, Matsubara A, Smiles K. The effect of 2% niacinamide on facial sebum production. J Cosmet Laser Ther. 2006;8(2):96-101. PubMed
• Navarrete-Solís J, Castanedo-Cázares JP, Torres-Álvarez B, et al. A double-blind, randomized clinical trial of niacinamide 4% versus hydroquinone 4% in the treatment of melasma. Dermatol Res Pract. 2011;2011:379173. PMC
• Barbosa M, de Amorim RP, Cassiano D, et al. Efficacy and safety of nicotinamide 10%, associated with magnesium ascorbyl phosphate 5% and hyaluronic acid 5%, compared to hydroquinone 4% in women with facial melasma. Clin Cosmet Investig Dermatol. 2024;17:2215-2223. PubMed
• Shalita AR, Smith JG, Parish LC, Sofman MS, Chalker DK. Topical nicotinamide compared with clindamycin gel in the treatment of inflammatory acne vulgaris. Int J Dermatol. 1995;34(6):434-437. PubMed
• Wohlrab J, Kreft D. Niacinamide, mechanisms of action and its topical use in dermatology. Skin Pharmacol Physiol. 2014;27(6):311-315. PubMed
• Cosmetic Ingredient Review Expert Panel. Final report of the safety assessment of niacinamide and niacin. Int J Toxicol. 2005;24(Suppl 5):1-31. PubMed
• Sjöberg T, Letasiova S, Jankovskaja S, et al. Effect of pH on niacinamide skin permeation. Sci Rep. 2026;16(1):9821. PMC
• Abraham AM, Afolabi OE, Anjani QK, Donnelly RF. PowderInjector microneedles: smart cavity microneedles as a novel intradermal delivery system for high doses of niacinamide. Int J Pharm. 2025;683:125992. PubMed
• Benyó Z, Gille A, Bennett CL, Clausen BE, Offermanns S. Nicotinic acid-induced flushing is mediated by activation of epidermal Langerhans cells. Mol Pharmacol. 2006;70(6):1844-1849. PubMed
• Javaid A, Mudavath SL. Niacin-induced flushing: mechanism, pathophysiology, and future perspectives. Arch Biochem Biophys. 2024;761:110163. PubMed
• Horimatsu T, Blomkalns AL, Ogbi M, et al. Niacin protects against abdominal aortic aneurysm formation via GPR109A independent mechanisms: role of NAD+/nicotinamide. Cardiovasc Res. 2020;116(14):2226-2238. PMC
• Tanno O, Ota Y, Kitamura N, Katsube T, Inoue S. Nicotinamide increases biosynthesis of ceramides as well as other stratum corneum lipids to improve the epidermal permeability barrier. Br J Dermatol. 2000;143(3):524-531. PubMed
• Soltani-Arabshahi R, Wong JW, Duffy KL, Powell DL. Facial allergic granulomatous reaction and systemic hypersensitivity associated with microneedle therapy for skin rejuvenation. JAMA Dermatol. 2014;150(1):68-72. PubMed

Last updated: August 20, 2026.