Niacinamide (nicotinamide) and hair & skin
What 2 graded rows on niacinamide (nicotinamide) agree on for hair & skin, 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 hair & skin
2 rows · 544 peopleSplit. 1 row found an improvement and 1 found no difference.
- BGrade B× 1
- DGrade D× 1
- Rows
- 2
- Trials
- 2
- People
- 544
Where they differ
From the rowsThe best-graded row, grade B, is a randomized trial of 386 people (2015) and found an improvement.
The row that found an improvement was larger: 386 people, against 158 people for the row that found no difference.
The row that found no difference is newer (2023) than the row that found an improvement (2015).
The best grade is B among the row that found an improvement, and D among the row that found no difference.
The rows
1 improved · 1 no difference- BGrade BNew non-melanoma skin cancers · Improved
RCT · n 386 · 2015 · Adults with at least two non-melanoma skin cancers in the past 5 years
1 g/day (500 mg twice daily) · 12 months
New non-melanoma skin cancers were 23% lower than with placebo; actinic keratoses were 11–20% lower; adverse events were similar.
Row on the Niacinamide (nicotinamide) page · PubMed 26488693 (opens PubMed)
- DGrade DNew keratinocyte cancers in transplant recipients · No difference
RCT · n 158 · 2023 · Organ-transplant recipients with at least two prior keratinocyte cancers
1 g/day (500 mg twice daily) · 12 months
207 new cancers with nicotinamide versus 210 with placebo; no difference in actinic keratoses or quality of life.
Row on the Niacinamide (nicotinamide) page · PubMed 36856616 (opens PubMed)