Niacinamide (nicotinamide) and skin cancer
What 2 graded rows on niacinamide (nicotinamide) agree on for skin cancer, and where they differ. Counted side by side, never averaged.
Consensus finder Rows from the Niacinamide (nicotinamide) page, reviewed Oct 21, 2026 How it decides
What the rows agree on
Each block and row is one graded row from the Niacinamide (nicotinamide) page, with its PubMed record.
Your question
Niacinamide (nicotinamide) and skin cancer
2 rows · 34,406 peopleSplit. 1 row found an improvement and 1 had mixed results.
- CGrade C× 2
- Rows
- 2
- Trials
- 5
- People
- 34,406
- Pooled reviews may count some twice
What the rows share
From the rowsThe best-graded row, grade C, is an observational study of 33,766 people (2025) and found an improvement.
The rows run from 640 to 33,766 people, published from 2023 to 2025: 1 pooled review and 1 single study.
The rows
1 improved · 1 mixed- CGrade CNew skin cancers in US veterans · Improved
Observational · n 33,766 · 2025 · US veterans with past skin cancers (mean age 77, 98% men); 12,287 prescribed nicotinamide matched to 21,479 who were not
1 g/day (500 mg twice daily) for more than 30 days · Records from 1999 to 2024
Skin cancer risk was 14% lower overall and 54% lower when nicotinamide was started after a first skin cancer. Transplant recipients showed no overall reduction.
Row on the Niacinamide (nicotinamide) page · PubMed 40960808 (opens PubMed)
- CGrade CNon-melanoma skin cancers (pooled trials) · Mixed
Meta-analysis, 4 studies · n 640 · 2023 · People at high risk of skin cancer in 4 Australian randomized trials, with normal or suppressed immunity
500 mg once or twice daily · 4 to 12 months
Pooled, new non-melanoma skin cancers were not significantly lower (rate ratio 0.82, 95% CI 0.61–1.12). The two trials in people with normal immunity found fewer cancers; the two transplant trials did not.
Row on the Niacinamide (nicotinamide) page · PubMed 38201930 (opens PubMed)