Niacinamide (Vitamin B3)
Niacinamide (Vitamin B3) — evidence, uses & status

Class: small_molecule
Synonyms: nicotinamide
vitamin B3
NAM
3-pyridinecarboxamide
INCI: Niacinamide
Function tags: skin appearance (cosmetic)
barrier support
hyperpigmentation appearance
antioxidant
sebum appearance
Overall evidence grade: A
WADA prohibited: no
Last updated: 2026-07-20

In brief: Niacinamide (nicotinamide, vitamin B3) is one of the best-evidenced cosmetic active ingredients. Multiple independent controlled human trials show measurable improvement in skin appearance related to hyperpigmentation, barrier function (reduced TEWL), and — at higher concentrations — fine lines and sebum. Effect sizes are modest compared with prescription retinoids or hydroquinone, but tolerability is much better and it plays well with almost every other active. It is a cornerstone cosmetic ingredient, not a hero molecule.

## Identity

a water-soluble amide form of **vitamin B3** (pyridine-3-carboxamide). It is the biologically active form used by the body to synthesise NAD+ and NADP+ — coenzymes central to cellular energy metabolism, DNA repair, and hundreds of enzymatic reactions. In skincare it is applied topically as a small, stable, well-tolerated molecule.

## Development & history

- Recognised as an essential nutrient in the 1930s (as part of the vitamin B complex, curing pellagra).
- Studied for cosmetic and dermatological uses since the 1970s.
- Emerged as a mainstream cosmetic active in the early 2000s, driven by Procter & Gamble research (Hakozaki, Bissett) demonstrating measurable effects on pigmentation, barrier, and skin appearance.
- Today it is one of the most-studied and most-used cosmetic ingredients, appearing in serums, moisturisers, sunscreens, and treatment products across every price tier.

## Mechanism (as proposed)

a small hydrophilic molecule that penetrates the stratum corneum readily. In keratinocytes it acts as a precursor to NAD+/NADP+, supporting cellular energy and repair. Documented mechanisms relevant to skin appearance include: reduced melanosome transfer from melanocytes to keratinocytes (mechanism behind the pigmentation effect); increased synthesis of ceramides and free fatty acids in the stratum corneum (mechanism behind the barrier effect); modulation of sebaceous lipogenesis; and antioxidant activity through NAD+-dependent enzymes.

Evidence grades by outcome:
outcome: Topical: hyperpigmentation (melasma, PIH, age spots) at 2–5%
grade: A
base: Multiple double-blind, split-face, vehicle-controlled RCTs (Hakozaki 2002 n=18 and n=79 dose-response; Kimball 2010; 2005 sallowness split-face n=~200); recent 2025 narrative reviews confirm consistent effect
effect: Measurable reduction of melanin transfer to keratinocytes; visible skin-tone improvement over 8–12 weeks
caveat: Smaller than hydroquinone in head-to-head trials; better tolerated; typically requires 8+ weeks of twice-daily use
outcome: Barrier function / TEWL (2–5%)
grade: A
base: Controlled trials showing measurable ceramide/free fatty acid synthesis increase and TEWL reduction; Kimball 10-week trial with 4% NAM + N-acetylglucosamine
effect: Improved stratum corneum integrity, reduced water loss
caveat: Formulation and vehicle matter; mechanism robust in vitro and in vivo
outcome: Fine lines and appearance of photoaging (5–6%)
grade: B
base: RCT of 6% niacinamide formulation reporting ~15% fine-line reduction; JAAD split-face sallowness study
effect: Modest visible improvement in appearance of fine lines and texture
caveat: Smaller than tretinoin/retinoids; multi-active formulations make isolated effect hard to prove
outcome: Sebum/oiliness reduction (2–4%)
grade: B
base: Multiple controlled trials at 2% and 4% for 2–4 weeks
effect: Measurable reduction in sebum excretion rate
caveat: Effect modest; some trials mixed; regional variability (better in Asian studies)
outcome: Acne vulgaris (topical 4%)
grade: B
base: Randomized trials vs clindamycin 1%; comparable efficacy on inflammatory lesions
effect: Reduction in inflammatory lesion count
caveat: Consumer skincare framing: use as appearance/comfort adjunct, not medicine
outcome: Systemic / oral high-dose "anti-aging" claims
grade: D
base: Small metabolic studies; oral NAM supplementation for photoprotection
effect: Oral 500 mg BID reduced non-melanoma skin cancer incidence in ONTRAC trial; unrelated to cosmetic topical claims
caveat: Systemic dosing outside cosmetic scope; do not conflate oral clinical data with topical serum claims
outcome: "High-strength 10%+" superiority over the proven 2–5% range
grade: D
base: Marketing claim
caveat: The comparison exists in humans — 2%, 5% and 10% tested on sebum and hydration — and 10% did not beat 5%. Every controlled result graded on this page sits at 2–6%. The extra strength adds flushing and tingling, not proportionate benefit.
outcome: Safety (topical)
base: Decades of widespread cosmetic use; controlled trials
effect: Generally well tolerated
caveat: Occasional mild flushing/tingling at higher concentrations; rare contact reactions; concentrations >10% not shown to add benefit

Legal status:
region: INT
status: Lawful cosmetic ingredient
note: Topical Niacinamide is a lawful cosmetic ingredient globally, including EU (Regulation (EC) 1223/2009), UK, US, and Asia. CosIng-listed. No concentration ceiling in the EU cosmetic framework; consumer formulas typically use 2–10%. Not a controlled or restricted substance.

Cosmetic claims:
allowed: for the appearance of a more even, brighter-looking complexion
helps improve the look of uneven skin tone
supports the appearance of a healthy skin barrier
for the look of smoother, more refined-looking skin
antioxidant
forbidden: treats melasma
treats hyperpigmentation
treats acne
inhibits melanogenesis
repairs the skin barrier
stimulates ceramide synthesis
reduces inflammation
anti-inflammatory
prevents skin cancer
reverses photoaging

Note: Niacinamide is a lawful cosmetic ingredient worldwide. Vallydia uses it in cosmetic serums at concentrations supported by clinical trials (2–10%) with appearance-only claims. Reference science below includes both topical cosmetic and higher-dose oral / medical uses; only topical cosmetic use is relevant to the sellable product.

Sources:
Hakozaki T, et al. The effect of niacinamide on reducing cutaneous pigmentation and suppression of melanosome transfer. Br J Dermatol. 2002; 147(1):20-31.
Bissett DL, et al. Topical niacinamide reduces yellowing, wrinkling, red blotchiness, and hyperpigmented spots in aging facial skin. Int J Cosmet Sci. 2004; 26(5):231-8.
Kimball AB, et al. Reduction in the appearance of facial hyperpigmentation after use of moisturizers with a combination of topical niacinamide and N-acetyl glucosamine. Br J Dermatol. 2010; 162(2):435-41.
Marques C, et al. Mechanistic Basis and Clinical Evidence for the Applications of Nicotinamide (Niacinamide) to Control Skin Aging and Pigmentation. Antioxidants (Basel). 2021; PMC8389214.
Sadler K, Kubiak K. Clinical Evaluation of Niacinamide in Hyperpigmentation and Barrier Repair. J Cosmo Tricho. 2025; 11:308.
Topical Niacinamide in Daily Skincare: A 3-Week Real-World Cosmetic Study. Appl Sci. 2025; 15(17):9729.