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Niacinamide

Also known as: niacinamide, vitamin B3, nicotinamide, topical niacinamide

Niacinamide, also called nicotinamide, is a form of vitamin B3 used topically for barrier, pigmentation, sebum and skin-ageing aims. Evidence exists across these areas, but effects are formulation- and outcome-specific; the breadth of research does not establish one universal concentration.

Evidence status

Moderate

Plausible mechanisms and small controlled studies support selected barrier, pigmentation, sebum and appearance outcomes. Evidence is narrow by claim, often short term, frequently manufacturer-authored, and does not establish that high concentrations outperform 2–5%.

Definition#

Niacinamide is a form of vitamin B3 used topically across barrier, pigmentation, sebum and skin-ageing aims. It is one of the few cosmetic actives with genuine mechanistic work behind it and a reputation for being well tolerated.

The honest framing is that its evidence is narrow by claim rather than broad. Each effect rests on its own study, at its own concentration, in its own population, over its own short timeframe. “Niacinamide is well studied” is true. “Therefore this niacinamide product does all of these things” does not follow.

Niacinamide is not niacin#

Niacinamide and nicotinamide are two names for the same amide form of vitamin B3. Nicotinic acid— usually called niacin — is a different molecule.[8]

This matters because niacin is the one associated with flushing. Most of the anxiety about niacinamide “causing a flush” is a confusion between the two names, and it feeds directly into the vitamin C myth further down this page.

Barrier and hydration#

The barrier case is the strongest mechanistic story niacinamide has. In cultured human keratinocytes, nicotinamide raised ceramide synthesis 4.1 to 5.5-fold, with glucosylceramide, sphingomyelin, free fatty acid and cholesterol synthesis also increasing. A separate 2% cream reduced transepidermal water loss and improved hydration in a 28-person left-right comparison in atopic dry skin.[1, 2]

Read those two findings for what they are. The fold-change is cell culture— it tells you the pathway is real, not how much lipid a given product puts into a given client’s stratum corneum. The TEWL result is human, but it is 28 people with atopic dry skin, which is not the same population as a client with a barrier compromised by over-exfoliation.

The Kanebo paper is also authored by a cosmetics manufacturer. That is worth knowing every time, not just once.

Pigmentation#

The best-known pigmentation work found something genuinely interesting: niacinamide reduced melanosome transfer from melanocytes to keratinocytes, without directly inhibiting tyrosinase or melanocyte melanin synthesis.[3]

That is a different mechanism from most pigment actives, and it is why niacinamide is often described as acting “downstream”. It also means the claim “niacinamide inhibits tyrosinase” is simply wrong — its own foundational paper says otherwise.

The clinical side is thinner than the mechanism suggests. The accompanying studies were short, in Japanese women, at specific concentrations — and the 2% arm was combined with sunscreen, which is not a neutral co-intervention in a pigmentation trial. A systematic review of natural ingredients in hyperpigmentation found the niacinamide findings promising within an evidence base limited by few trials and short follow-up.[3, 10]

One scope note that matters clinically: this evidence is about facial hyperpigmented spots and UV-induced pigmentation. No cited study assessed post-inflammatory hyperpigmentation specifically, and the one included study that measured it found no between-side benefit. For PIH the priority remains what it always is — controlling the trigger. See the underarm hyperpigmentation guide for that reasoning worked through.

Sebum#

Niacinamide’s sebum reputation rests on a paper reporting two studies of 2% niacinamide that disagreed with each other. Japanese and US participant groups produced different outcomes, and the two studies measured different things — sebum excretion rate in one, casual sebum levels in the other.[5]

Two studies, two populations, two endpoints, two answers. That is not a basis for telling a client niacinamide will control their oil. It is a basis for saying it might, and that you will look together at whether it does.

Appearance of ageing#

A 12-week split-face study of a 5% niacinamide formula in 50 white women reported improvements against a matched moisturiser vehicle across several appearance measures including yellowing, wrinkling, red blotchiness and hyperpigmented spots.[4]

It is a reasonable study with a sensible comparator — matched vehicle rather than nothing, which is better than much of the category. It is also 12 weeks, 50 people, one demographic, one formulation, and authored at Procter & Gamble. Every one of those is a limit on how far the result travels.

Acne#

This is where the gap between reputation and evidence is widest. A review of nicotinamide in acne concluded the effect of topical and oral nicotinamide remained unclearbecause the available literature was limited. A split-face study adding 5% niacinamide to 2.5% benzoyl peroxide — in 21 participants— produced mixed outcomes across acne, sebum, erythema and pigmentation.[6, 9, 11]i

Set that against what UK guidance actually recommends first-line for acne: topical adapalene, topical tretinoin, benzoyl peroxide, topical clindamycin and oral tetracyclines, in defined combinations. Niacinamide does not appear.

It can sit alongside a proper acne plan. It is not a substitute for one, and presenting it as such to a client with inflammatory acne delays treatment that works.

How much is enough?#

Almost all the clinical work above used 2% to 5%. Products marketed at 10%, 15% or 20% are not supported by a corresponding body of evidence showing they do more.[7, 8]i

Be careful not to overcorrect, though. The popular counter-claim — that high-percentage niacinamide is more irritating — does not have controlled data behind it either. The honest position is that above about 5% you are paying for a number that has not been shown to buy you anything, not that you are harming the skin.

The vitamin C question#

You will have been told never to layer niacinamide with vitamin C — that they cancel each other out, or convert to niacin and cause flushing. It is probably the most repeated rule in skincare. It does not survive reading the paper it comes from.

What the source actually is

The rule traces to a 1968 Japanese analytical-chemistry paper that ran polarography on nicotinamide and ascorbic acid in aqueous solution and observed a yellow charge-transfer complex.[12]

That study contained:

  • no skin;
  • no finished cosmetic product;
  • no efficacy endpoint;
  • no harm endpoint;
  • and no measurement of niacin formation at all.

It is a test-tube observation about the behaviour of two molecules in water. It was never a study about putting serums on a face.

Correcting the correction

Here is where even the debunk usually goes wrong. The rebuttal you will read is that the 1968 work used concentrated solutions, far above cosmetic levels. That has it backwards. The concentrations were 0.05 M each — roughly 0.6% niacinamide and 0.9% ascorbic acid, about ten times below the levels in a typical product.

We flag this because the concentration argument invites an obvious rebuttal, and the real argument does not need it. The point is not that the solutions were too strong. The point is that a polarography experiment with no skin, no product and no outcome measure cannot tell you what happens when a client applies two serums.

The practical answer: there is no good evidence that layering modern finished niacinamide and vitamin C products is ineffective or harmful. If a particular pairing stings a particular client, that is a formulation and tolerance question for that client — not a law of chemistry.

In professional practice#

  • Match the claim to the evidence. Barrier and pigmented spots are the better-supported uses. Sebum is contested. Acne is weak.
  • 2–5% is the evidenced range. A higher number on the box is a marketing decision, not a clinical one.
  • It is an adjunct, not a plan. For acne or PIH the trigger comes first; niacinamide supports, it does not lead.
  • Tolerance is its real strength. Its value in practice is often that a compromised client can use it while everything else is paused.
  • Retire the vitamin C rule— and be ready to explain why, because clients will have read the opposite.

Cautions#

Niacinamide is generally well tolerated, which is much of its appeal. The cautions are mostly about expectation and context rather than harm:

  • it is not a treatment for inflammatory acne and should not delay one;
  • it has not been shown to resolve post-inflammatory hyperpigmentation specifically;
  • stinging on application is a formulation and barrier-state issue, not proof of a chemical incompatibility;
  • a client with an unexplained or changing pigmented lesion needs medical assessment, not an active.

What the evidence currently supports#

Mechanistically, the barrier-lipid pathway and the melanosome-transfer finding are well described and interesting. Clinically, there are small controlled studies supporting reduced TEWL and improved hydration in dry skin, and improvement in facial hyperpigmented spots and several appearance measures at 5% against vehicle.

What the evidence does not support is a single universal concentration, equivalence with guideline acne treatment, a demonstrated benefit in PIH, or a consistent sebum effect. And a material share of the foundational work comes from companies that sell the ingredient.

What remains uncertain#

  • Whether any single molecular target explains the range of claimed effects — no convincing one has been established.[8]
  • Whether concentrations above 5% add clinical benefit.
  • Whether niacinamide does anything useful in PIH specifically.
  • Why the two sebum studies disagreed — population, endpoint, or both.
  • How much of the appearance benefit at 5% is niacinamide and how much is twelve weeks of consistent moisturiser use.

Common misconceptions#

“Niacinamide and vitamin C cancel each other out.”

No. The claim rests on 1968 test-tube polarography with no skin, no product and no outcome measure — at concentrations well below cosmetic levels.[12]

“Niacinamide inhibits tyrosinase.”

Its own foundational paper says the opposite: it reduced melanosome transfer without inhibiting tyrosinase.[3]

“Higher percentages work better.”

Not shown. Nearly all the clinical work sits at 2–5%.[7, 8]i

“It causes flushing.”

That is niacin — nicotinic acid — a different molecule.[8]

“It treats acne.”

The evidence is limited and mixed, and it is not among the UK first-line recommended options.[6, 9, 11]i

Frequently asked questions#

Can a client use niacinamide and vitamin C together?

On the available evidence, yes. The incompatibility claim comes from a test-tube study with no skin and no product. If a specific pairing stings, treat that as a tolerance issue for that client.[12]

What percentage should I recommend?

Something in the 2–5% range matches where the clinical evidence actually sits. Higher numbers have not been shown to do more.[7, 8]i

Will it help post-inflammatory hyperpigmentation?

Unknown. The pigmentation evidence is in facial hyperpigmented spots and UV-induced pigmentation, not PIH, and the one cited study that measured PIH found no between-side benefit. Control the trigger first.[3, 10]

Is it safe in pregnancy?

We do not know, and neither does anyone else from the evidence. This review did not identify pregnancy-specific clinical safety evidence for the topical cosmetic formulations discussed here.[no source found] Niacinamide is not among the actives ordinarily restricted in pregnancy and it is commonly chosen when retinoids are stopped — but customary use and “it is a vitamin derivative” are conventions, not data, and this page previously offered them as reassurance.

Pregnancy does not automatically make niacinamide unsafe. Product choice, and the treatment of any skin condition in pregnancy, belong with the client’s own appropriately qualified clinician rather than with the treatment room.

Why does so much of the research come from manufacturers?

Because cosmetic ingredients rarely attract independent funding. Manufacturer-authored work is not automatically wrong — but it is not independent, and an entry that quotes the findings while hiding the authorship is doing the reader a disservice. We name it on each source in the reference list below.

References#

Each source is graded by evidence tier. Tier 4 material (manufacturer documents, expert consensus, practitioner experience) is useful for protocol and context, and is never presented as equivalent to independent clinical evidence.

  1. 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. British Journal of Dermatology. 2000;143(3):524–531.Tier 3Supports: In cultured human keratinocytes, nicotinamide raised ceramide synthesis 4.1–5.5-fold, with glucosylceramide, sphingomyelin, free fatty acid and cholesterol synthesis also increased. Separate in-vivo work reported increased stratum-corneum lipids and reduced TEWL in dry skin.Funding / interest: Authored at Kanebo Ltd, a cosmetics manufacturer.
  2. Soma Y, Kashima M, Imaizumi A, et al. Moisturizing effects of topical nicotinamide on atopic dry skin. International Journal of Dermatology. 2005;44(3):197–202.Tier 2Supports: A 2% nicotinamide cream reduced TEWL and improved hydration in a 28-person left-right comparison in atopic dry skin.
  3. Hakozaki T, Minwalla L, Zhuang J, et al. The effect of niacinamide on reducing cutaneous pigmentation and suppression of melanosome transfer. British Journal of Dermatology. 2002;147(1):20–31.Tier 2Supports: Niacinamide reduced melanosome transfer from melanocytes to keratinocytes without inhibiting tyrosinase or melanocyte melanin synthesis. Accompanying short clinical studies in Japanese women: 5% niacinamide versus vehicle in facial hyperpigmentation (n=18), and a 2% arm combined with sunscreen.Funding / interest: Authored at Procter & Gamble Far East, which sells niacinamide skincare.
  4. Bissett DL, Miyamoto K, Sun P, Li J, Berge CA. Topical niacinamide reduces yellowing, wrinkling, red blotchiness, and hyperpigmented spots in aging facial skin. International Journal of Cosmetic Science. 2004;26(5):231–238.Tier 2Supports: A 12-week 5% niacinamide split-face study in 50 white women reported improvements versus a matched moisturiser vehicle across several appearance measures.Funding / interest: Authored at Procter & Gamble.
  5. Draelos ZD, Matsubara A, Smiles K. The effect of 2% niacinamide on facial sebum production. Journal of Cosmetic and Laser Therapy. 2006;8(2):96–101.Tier 2Supports: Two controlled studies produced different sebum findings in Japanese and US participant groups, measuring different endpoints (sebum excretion rate versus casual sebum levels).Funding / interest: Co-authors Matsubara and Smiles were at Procter & Gamble.
  6. Walocko FM, Eber AE, Keri JE, Al-Harbi MA, Nouri K. The role of nicotinamide in acne treatment. Dermatologic Therapy. 2017;30(5):e12481.Tier 4Supports: The effect of topical and oral nicotinamide on acne remained unclear because the available literature was limited.
  7. Ong RR, Goh CF. Niacinamide: a review on dermal delivery strategies and clinical evidence. Drug Delivery and Translational Research. 2024;14(12):3512–3548.Tier 4Supports: Formulation-dependent permeation. NOTE: full text is paywalled; the abstract describes 'proven efficacy', so this source is cited only for delivery/permeation and not for any limitation of the clinical evidence.
  8. Boo YC. Mechanistic Basis and Clinical Evidence for the Applications of Nicotinamide (Niacinamide) to Control Skin Aging and Pigmentation. Antioxidants. 2021;10(8):1315.Tier 4Supports: NAD-related biological context, and the absence of convincing evidence for one specific molecular target controlling skin ageing and pigmentation.
  9. Kaewsanit T, Chakkavittumrong P, Waranuch N. Clinical Comparison of Topical 2.5% Benzoyl Peroxide plus 5% Niacinamide to 2.5% Benzoyl Peroxide Alone in the Treatment of Mild to Moderate Facial Acne Vulgaris. Journal of Clinical and Aesthetic Dermatology. 2021;14(6):53–59.Tier 2Supports: A 12-week split-face study in 21 participants. Mixed acne, sebum, erythema and pigmentation outcomes for benzoyl peroxide with or without 5% niacinamide.
  10. Hollinger JC, Angra K, Halder RM. Are Natural Ingredients Effective in the Management of Hyperpigmentation? A Systematic Review. Journal of Clinical and Aesthetic Dermatology. 2018;11(2):28–37.Tier 1Supports: Promising niacinamide pigmentation findings within an evidence base limited by few clinical trials and short follow-up.
  11. National Institute for Health and Care Excellence. Acne vulgaris: management. NICE guideline NG198.Tier 1Supports: First-line acne options FOR ENGLAND — available for use in Wales but not mandatory there, and reviewed and endorsed separately in Northern Ireland; Scotland has its own arrangements. They include topical adapalene, topical tretinoin, benzoyl peroxide, topical clindamycin and oral tetracyclines in defined combinations. Niacinamide does not appear as a recommended option.
  12. Okazaki Y, Otsuki T, Miyasaka K, Nabikawa T. The behaviors of nicotinamide–ascorbic acid complex. Polarographic studies of charge-transfer complexes. Bunseki Kagaku. 1968;17(10):1228–1232.In vitroTier 3Supports: Polarography of nicotinamide and ascorbic acid in aqueous solution, forming a yellow charge-transfer complex. Concentrations were 0.05 M each — roughly 0.6% niacinamide and 0.9% ascorbic acid, BELOW typical cosmetic use levels, not above them. No skin, no finished product, no efficacy endpoint, no harm endpoint, and no measurement of niacin formation.

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Skinipedia is written by the educators at MSTA, the medic-led skincare training academy in Liverpool.