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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%.

What niacinamide is, and the forms of vitamin B3#

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 it has a long-standing reputation for being well tolerated.

Niacinamide and nicotinamide are two names for the same amide form of vitamin B3. Nicotinic acid— usually called niacin — is a different form of the vitamin, and the names are not interchangeable.[8]

The evidence behind the ingredient 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. The literature is genuinely there; it belongs to particular claims, and it does not transfer between them.

Use of niacinamide in aesthetic practice#

Niacinamide is a cosmetic active. Selecting a product, recommending it and retailing it are all yours, and nothing in the category requires a prescriber.

Its role in a plan is adjunctive. Barrier support and a tolerated daily routine are what it contributes; a condition with guideline treatment behind it — inflammatory acne above all — is treated on that guideline, with niacinamide alongside it rather than in place of it. The evidence for that boundary is set out under clinical uses.

Contraindications and cautions#

Niacinamide is well tolerated, and much of its practical value follows from that. The cautions are largely about context and expectation rather than about harm.

Pregnancy

No pregnancy-specific clinical safety evidence exists 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 the fact that it is a vitamin derivative, are conventions rather than data.

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.

Undiagnosed and changing pigmented lesions

A client with an unexplained or changing pigmented lesion needs medical assessment rather than an active. The pigmentation evidence below concerns facial hyperpigmented spots and UV-induced pigmentation, and an undiagnosed lesion sits outside it.

Clinical uses and the evidence behind them#

Barrier function and hydration

This is the strongest case 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]

The two findings carry different weight. The fold change is cell culture: it establishes that the pathway is real, rather than measuring how much lipid a given product puts into a given client’s stratum corneum. The TEWL result is human, and it is 28 people with atopic dry skin — a different population from a client whose barrier has been compromised by over-exfoliation. The keratinocyte paper was authored at a cosmetics manufacturer.

Facial hyperpigmented spots

The best-known pigmentation work found that 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”.

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]

The scope of that evidence is 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.

The 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]

The comparator is the strength of it: a matched vehicle rather than nothing, which is better than much of the category. The limits travel with the result — 12 weeks, 50 people, one demographic, one formulation, and authorship at Procter & Gamble. Each is a limit on how far the finding travels.

Sebum

The sebum reputation rests on one 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 endpoints — sebum excretion rate in one, casual sebum levels in the other.[5]

Two populations, two endpoints, two answers. The supportable position is that a sebum effect is possible and unproven, which makes it something to observe in a particular client rather than something to promise one.

Acne vulgaris

This is the weakest indication, and the widest gap between reputation and evidence. A review of nicotinamide in acne concluded that the effect of topical and oral nicotinamide remained unclearbecause the available literature was limited, and 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

NICE recommends topical adapalene, topical tretinoin, benzoyl peroxide, topical clindamycin and oral tetracyclines first-line, in defined combinations. Niacinamide does not appear among them.[6, 9, 11]i

It can sit alongside a proper acne plan. Where it is presented as a substitute for one, the cost falls on a client with inflammatory acne as a delay to treatment that works.

Selecting a niacinamide product#

Two decisions carry most of the weight: the concentration, and what the product is being asked to do.

Concentration

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 that they do more.[7, 8]i The evidenced range is therefore the one a selection can be matched to, and a higher number on the box is a marketing decision rather than a clinical one.

Matching the product to the aim

Barrier support and facial hyperpigmented spots are the better-supported aims. Sebum is contested and acne is the weakest, and a claim made to a client is only as strong as the part of the evidence base it comes from.

Tolerance

Tolerance is niacinamide’s real strength in practice. Its value is often that a compromised client can continue using it while everything else is paused, which is a property of the finished formulation as much as of the ingredient.

Adverse effects and their management#

Expected local effects

Niacinamide is generally well tolerated, and stinging on application is the effect most often reported. It is a formulation and barrier-state matter rather than evidence of a chemical incompatibility.

The flush associated with vitamin B3

The flush that clients associate with vitamin B3 belongs to nicotinic acid, which is a different form of the vitamin from the amide form used in these products.[8]

Reducing, stopping and referring

Where a particular product or pairing stings a particular client, it is handled as a tolerance question for that client: the finished formulation is the variable, and none of the sources reviewed here establishes a threshold at which niacinamide itself is reduced or stopped.

Referral in this category follows the condition rather than the ingredient, and the situations that call for it are set out below.

Referral and scope boundaries#

Niacinamide sits wholly within cosmetic practice, so the boundaries here concern the conditions it is asked to treat rather than the ingredient itself. Referral is indicated in three situations:

  • Inflammatory acne requiring guideline treatment. The evidence that works in acne sits with medicines, which makes referral a routine part of competent practice here rather than a limitation of it.
  • An unexplained or changing pigmented lesion, which needs medical assessment before any active is considered.
  • Pregnancy, where product choice and the treatment of any skin condition belong with the client’s own appropriately qualified clinician.

Barrier support and adherence to a tolerated routine continue alongside another clinician. They account for a substantial part of the result and require no prescription.

Mechanism of action#

The mechanistic work sits in two places. In cultured human keratinocytes, nicotinamide raised the synthesis of ceramides and of the other stratum corneum lipids — glucosylceramide, sphingomyelin, free fatty acids and cholesterol — which is the basis of the barrier account.[1, 2] In pigment, it reduced the transfer of melanosomes from melanocytes to keratinocytes while leaving tyrosinase and melanocyte melanin synthesis directly uninhibited, which places its effect downstream of melanin production.[3]

The two accounts were arrived at separately, in different models, and they are described separately for that reason.

Commonly misstated claims#

Four statements circulate widely in the trade. Each is set out below with what the primary literature was found to support.

“Niacinamide and vitamin C cancel each other out.”

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. The concentrations were 0.05 M each— roughly 0.6% niacinamide and 0.9% ascorbic acid, about ten times below typical cosmetic use levels. The study involved no skin, no finished product, no efficacy endpoint, no harm endpoint, and no measurement of niacin formation at all.[12]

Supported statement: a test-tube observation about two molecules in water, and no evidence either way about two finished products applied to a face.

“Niacinamide inhibits tyrosinase.”

Its own foundational paper reports the opposite finding. Melanosome transfer to keratinocytes was reduced, and tyrosinase and melanocyte melanin synthesis were left directly uninhibited.[3]

Supported statement: niacinamide acts downstream of melanin synthesis, by reducing the transfer of melanosomes to keratinocytes.

“Higher percentages work better.”

Almost all the clinical evidence sits at 2–5%, and no corresponding body of work establishes that 10% or 20% achieves more.[7, 8]iThe popular counter-claim — that high-percentage niacinamide is more irritating— has no controlled data behind it either.

Supported statement: above about 5% the number has not been shown to buy anything, in either direction.

“Niacinamide is well studied.”

The statement is true; the inference usually drawn from it is not. The clinical work is made up of few, short, formulation-specific studies in narrow populations.[3, 10]Several of the foundational papers were authored at companies that sell niacinamide skincare — Kanebo for the barrier work, Procter & Gamble for the pigmentation, appearance and sebum work. That does not make them wrong; it does mean they are not independent, and the funding is named on each source in the reference list below.

Supported statement: niacinamide is well studied claim by claim, and the breadth of the literature does not transfer from one claim to the next.

Areas of remaining uncertainty#

  • Whether any single molecular target explains the range of claimed effects — no convincing one has been established.[8] Each claim therefore stands or falls on its own study.
  • Whether concentrations above 5% add clinical benefit. Until that is measured, the 2–5% range is the defensible basis for a recommendation.
  • Whether niacinamide does anything useful in post-inflammatory hyperpigmentation specifically. While that is open, trigger control remains the priority in PIH.
  • Why the two sebum studies disagreed — population, endpoint, or both. Until it is resolved, a sebum effect is something to observe in a client rather than to promise one.
  • How much of the appearance benefit at 5% belongs to niacinamide and how much to twelve weeks of consistent moisturiser use. The routine is part of the result, and is worth describing to a client that way.

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 finished product.[12] Where a specific pairing stings, that is a tolerance question for that client rather than a law of chemistry.

What concentration does the evidence support?

2–5%. That is where almost all the clinical work sits, and higher numbers have not been shown to achieve more.[7, 8]i

Will it help post-inflammatory hyperpigmentation?

Unknown. The pigmentation evidence is in facial hyperpigmented spots and UV-induced pigmentation rather than PIH, and the one cited study that measured PIH found no between-side benefit.[3, 10] Controlling the trigger comes first.

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.