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Niacinamide

Evidence Fact Sheet

Nicotinamide · Vitamin B3 amide form

Niacinamide (nicotinamide), the amide form of vitamin B3, is an NAD+ salvage-pathway substrate studied both orally (skin-cancer chemoprevention, retinal/NAD+ support) and topically (skin appearance, pigmentation). GRAS in the US; authorized B3 health claims in the EU and Brazil. Evidence includes a positive chemoprevention meta-analysis and a prominent null transplant trial.

Also known as: Nicotinamide · Vitamin B3 (amide form) · Nicotinic Acid Amide · Vitamin PP (amide form)

Overview

Niacinamide (nicotinamide) is the amide form of vitamin B3 and a substrate for the NAD+ salvage pathway, with additional mechanisms including PARP modulation at high doses and topical skin-barrier support. Research doses range from the 14-18 mg/day RDA for B3-deficiency prevention up to 500-1500 mg/day as an oral NAD+ precursor (with hepatotoxicity caution above roughly 3 g/day), plus topical formulations around 2-5%. It is studied across dermatology (skin-cancer chemoprevention, aging skin appearance, pigmentation) and emerging NAD+/ophthalmology contexts. Regulatory status: GRAS in the US (vitamin B3 amide form), EFSA-authorized vitamin B3 health claims in the EU, ANVISA functional claims in Brazil, and a permitted nutrient source in China under GB 14880. This page reports research findings in studied populations and is not disease-treatment guidance.

Mechanism of Action

NAD+ salvage substrate · PARP inhibition (high dose) · Sirtuin modulation · Topical skin barrier support

Body systems: Skin & Connective Tissue · METABOLISM · Mitochondrial & Cellular Energy

Evidence-Based Benefits

Each benefit below is anchored to a specific PubMed-indexed study. Effect sizes, sample sizes, and p-values are reported as published; no values are inferred. Honest negatives and null results are kept alongside the positive findings, and disease-research populations are described as such — Niacinamide is not characterized as a treatment for any disease.

Skin-Cancer Chemoprevention (Pooled Evidence)

Meta-analysis supported
  • 0.50rate ratio · all skin cancers
  • 0.29-0.8595% CI
  • 5 trials · 552pooled trials · patients

In a systematic review and meta-analysis of randomized controlled trials, oral nicotinamide was associated with a significant reduction in skin cancers (all types) versus control, with moderate strength of evidence. The pooled estimate also showed significant reductions in basal-cell and squamous-cell carcinomas, alongside an increased risk of digestive adverse effects.

Reported effect: rate ratio 0.50 (95% CI, 0.29-0.85; I2 = 64%; 552 patients; 5 trials); 29 trials (3039 patients) met inclusion criteria overall

“We screened 4730 citations and found 29 trials (3039 patients) meeting inclusion criteria. Nicotinamide was associated with a significant reduction in skin cancers compared to control (rate ratio 0.50 (95% CI, 0.29-0.85; I2 = 64%; 552 patients; 5 trials); moderate strength of the evidence).”

Source: PMID 35134311 · Mainville 2022 · J Cutan Med Surg

Skin-Cancer Chemoprevention (Immunocompetent RCT · ONTRAC)

RCT supported
  • 23%lower rate · p=0.02
  • 4 to 3895% CI (%)
  • 386participants

In a phase 3 randomized trial in high-risk immunocompetent adults with prior nonmelanoma skin cancers, oral nicotinamide 500 mg twice daily for 12 months lowered the rate of new nonmelanoma skin cancers relative to placebo. This is the landmark positive chemoprevention trial often cited for niacinamide.

Reported effect: rate of new nonmelanoma skin cancers lower by 23% (95% CI, 4 to 38) vs placebo (P=0.02), 500 mg twice daily, 12 months, 386 participants

“At 12 months, the rate of new nonmelanoma skin cancers was lower by 23% (95% confidence interval [CI], 4 to 38) in the nicotinamide group than in the placebo group (P=0.02).”

Source: PMID 26488693 · Chen 2015 · N Engl J Med

Skin-Cancer Chemoprevention (Transplant Recipients · Honest Negative)

Null / no benefit RCT supported
  • 1.0rate ratio · p=0.96
  • 0.8 to 1.395% CI
  • 207 vs 210new cancers (niac vs placebo)

In immunosuppressed solid-organ transplant recipients, the same 500 mg twice-daily nicotinamide regimen did NOT reduce keratinocyte cancers or actinic keratoses over 12 months — a prominent null result that contrasts with the positive ONTRAC trial in immunocompetent patients. The trial was stopped early for poor recruitment.

Reported effect: 207 new keratinocyte cancers (nicotinamide) vs 210 (placebo); rate ratio 1.0 (95% CI 0.8 to 1.3; P=0.96); 158 participants

“At 12 months, there were 207 new keratinocyte cancers in the nicotinamide group and 210 in the placebo group (rate ratio, 1.0; 95% confidence interval, 0.8 to 1.3; P = 0.96).”

Source: PMID 36856616 · Allen 2023 · N Engl J Med

Topical Aging-Skin Appearance

RCT supported

In a double-blind, split-face randomized trial, topical 5% niacinamide applied twice daily for 12 weeks improved multiple cosmetic skin-appearance endpoints versus vehicle, including fine lines/wrinkles, hyperpigmented spots, red blotchiness, sallowness, and elasticity. The abstract reports direction of effect rather than pooled numeric effect sizes for each endpoint.

Effect size: this study reports the direction of the finding but does not state a specific numeric effect size, so none is given here rather than estimated.

“reductions in fine lines and wrinkles, hyperpigmented spots, red blotchiness, and skin sallowness (yellowing). In addition, elasticity (as measured via cutometry) was improved.”

Source: PMID 16029679 · Bissett 2005 · Dermatol Surg

Skin Pigmentation / Lightening (Topical)

RCT supported
  • 35-68%melanosome-transfer inhibition
  • 4 weeksduration
  • 18 · 120subjects (two studies)

Niacinamide inhibited melanosome transfer in a coculture model by 35-68% and, in clinical testing, significantly decreased facial hyperpigmentation and increased skin lightness versus vehicle after 4 weeks. Topical concentrations were 5% (hyperpigmentation study, 18 subjects) and 2% with sunscreen (facial tanning study, 120 subjects).

Reported effect: 35-68% inhibition of melanosome transfer in coculture; significant decrease in hyperpigmentation and increased skin lightness vs vehicle after 4 weeks (5% in 18 subjects; 2% + sunscreen in 120 subjects)

“niacinamide gave 35-68% inhibition of melanosome transfer in the coculture model ... niacinamide significantly decreased hyperpigmentation and increased skin lightness compared with vehicle alone after 4 weeks”

Source: PMID 12100180 · Hakozaki 2002 · Br J Dermatol

Inner-Retinal Function (Glaucoma)

RCT supported
  • 14.8%PhNR Vmax · p=0.02
  • 12.6%Vmax ratio · p=0.002
  • 57participants

In a crossover randomized clinical trial in glaucoma patients, high-dose oral nicotinamide (1.5 g/day then 3.0 g/day) improved an electroretinography marker of inner-retinal function (photopic negative response) over each 12-week phase, with statistically significant gains versus the placebo phase. This is an emerging ophthalmology research direction, not established glaucoma therapy.

Reported effect: PhNR Vmax improved 14.8% (95% CI 2.8-26.9%, P=0.02) on nicotinamide vs 5.2% (P=0.27) on placebo; Vmax ratio improved 12.6% (P=0.002) vs 3.6% (P=0.30); 57 participants

“PhNR Vmax improved by 14.8% [95% CI: 2.8%, 26.9%], (P = .02) on nicotinamide and 5.2% [-4.2%, 14.6%], (P = .27) on placebo. Vmax ratio improved by 12.6% [5.0%, 20.2%], (P = .002) following nicotinamide, 3.6% [-3.4%, 10.5%], (P = .30) on placebo.”

Source: PMID 32721104 · Hui 2020 · Clin Exp Ophthalmol

Dosage (research context · not a recommendation)

14-18 mg/day RDA (B3 deficiency prevention) · 500-1500 mg/day NAD+ precursor (Tier C · caution hepatotoxicity > 3 g/day) · 5% topical (Bissett 2005 PMID 16029679 skin RCT)

Regulatory Status · 4 Markets

US · FDA
GRAS (vitamin B3 amide form)
EU · EFSA
Reg 432/2012 authorized health claims · 6 niacin claims (vitamin B3 family)
CN · China
Established nutrient — SAMR-permitted vitamin B3 source (amide form) under GB 14880 food-fortifier standard (NRV 15 mg/day); eligible for health-food, sports-nutrition and general food fortification, and the vitamin B3 health-food function is within the registrable function catalog.
BR · ANVISA
IN 28/2018 Anexo V "niacina" · 4 functional claims (pele · mucosas · metabolismo energético · metabolismo de proteínas/carboidratos/gorduras) · threshold ≥ 2.4 mg/dia adultos ≥ 19 anos per Anexo III

Authorized Claims

EFSA — “Niacin contributes to normal energy-yielding metabolism” (Reg 432/2012 Annex · authorized health claim · EFSA Journal 2009;7(9):1224)

EFSA — “Niacin contributes to normal functioning of the nervous system” (Reg 432/2012 Annex · authorized health claim · EFSA Journal 2009;7(9):1224)

EFSA — “Niacin contributes to normal psychological function” (Reg 432/2012 Annex · authorized health claim · EFSA Journal 2010;8(10):1757)

EFSA — “Niacin contributes to the maintenance of normal mucous membranes” (Reg 432/2012 Annex · authorized health claim · EFSA Journal 2009;7(9):1224)

EFSA — “Niacin contributes to the maintenance of normal skin” (Reg 432/2012 Annex · authorized health claim · EFSA Journal 2009;7(9):1224 + 2010;8(10):1757)

EFSA — “Niacin contributes to the reduction of tiredness and fatigue” (Reg 432/2012 Annex · authorized health claim · EFSA Journal 2010;8(10):1757)

ANVISA — “A niacina auxilia no metabolismo energético.” (IN 28/2018 Anexo V · alegação funcional autorizada)

ANVISA — “A niacina auxilia no metabolismo de proteínas, carboidratos e gorduras.” (IN 28/2018 Anexo V · alegação funcional autorizada)

ANVISA — “A niacina contribui para a manutenção da pele.” (IN 28/2018 Anexo V · alegação funcional autorizada)

ANVISA — “A niacina auxilia na manutenção de mucosas.” (IN 28/2018 Anexo V · alegação funcional autorizada)

Safety

Hepatotoxicity reported at sustained > 3 g/day systemic intake (UL guidance threshold) · pregnancy generally safe at RDA · topical 5% well-tolerated in 12-week trial

Goals: skin-beauty · longevity-stack

Lifestyles: senior-60-plus

References

PubMed-indexed citations anchoring the benefit findings above. Effect sizes are reported as published.

  1. PMID 35134311 · Mainville 2022 · J Cutan Med Surg — Skin-Cancer Chemoprevention (Pooled Evidence)
  2. PMID 26488693 · Chen 2015 · N Engl J Med — Skin-Cancer Chemoprevention (Immunocompetent RCT · ONTRAC)
  3. PMID 36856616 · Allen 2023 · N Engl J Med — Skin-Cancer Chemoprevention (Transplant Recipients · Honest Negative)
  4. PMID 16029679 · Bissett 2005 · Dermatol Surg — Topical Aging-Skin Appearance
  5. PMID 12100180 · Hakozaki 2002 · Br J Dermatol — Skin Pigmentation / Lightening (Topical)
  6. PMID 32721104 · Hui 2020 · Clin Exp Ophthalmol — Inner-Retinal Function (Glaucoma)

Frequently Asked Questions

1. What is niacinamide and how does it differ from niacin?

Niacinamide (nicotinamide) is the amide form of vitamin B3. It feeds the NAD+ salvage pathway and, at high doses, can modulate PARP enzymes; topically it supports the skin barrier. Unlike niacin (nicotinic acid), niacinamide does not typically cause the skin-flushing reaction associated with lipid-lowering niacin doses. This page reports research findings, not disease treatment.

2. What does the strongest evidence show for skin-cancer chemoprevention?

A meta-analysis of randomized trials (Mainville 2022, PMID 35134311) found oral nicotinamide associated with a significant reduction in skin cancers (rate ratio 0.50, 95% CI 0.29-0.85; 5 trials, 552 patients). The landmark ONTRAC RCT (Chen 2015, PMID 26488693) showed a 23% lower rate of new nonmelanoma skin cancers in immunocompetent adults at 500 mg twice daily.

3. Does niacinamide work for everyone at risk of skin cancer?

No — the evidence includes an important honest negative. In immunosuppressed organ-transplant recipients (Allen 2023, PMID 36856616), the same 500 mg twice-daily regimen did not lower keratinocyte cancers (207 vs 210; rate ratio 1.0, P=0.96). The chemoprevention benefit seen in immunocompetent patients did not carry over to that transplant population.

4. What are the typical research doses studied?

Topical dermatology trials used roughly 2-5% niacinamide (e.g. 5% over 12 weeks in Bissett 2005, PMID 16029679). Oral chemoprevention trials used 500 mg twice daily, and the glaucoma retinal-function study (Hui 2020, PMID 32721104) used 1.5-3.0 g/day. As an oral NAD+ precursor the studied range is broadly 500-1500 mg/day, with hepatotoxicity caution above about 3 g/day. This is an evidence summary, not dosing guidance.

Last evidence review: 2026-06-08

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