A Double-Blind, Randomized Clinical Trial of Niacinamide 4% versus Hydroquinone 4% in the Treatment of Melasma

Table 1

Changes in MASI scores and colorimetric values for 4% HQ and 4% niacinamide-treated sides in 27 patients with melasma. Mast cell counts and melanin expression initially and after treatment with niacinamide in 11 patients.

	HQ			Niacinamide
	Onset	8 wk	𝑃	Onset	8 wk	𝑃
MASI	4 (.9–1.8)	1.2 (.8–1.6)	<0.001	3.7 (2.9–4.4)	1.4 (3.3–4.7)	<0.001
L* axis	50.9 (49.1–52.6)	56 (54.6–57.4)	<0.001	51.1(49.3–52.9)	56 (54.4–57.5)	<0.001
a* axis	12.9 (12.3–13.5)	13.6 (12.6–14)	0.25	12.8 (12.1–13.5)	13.6 (12.7–14.5)	0.08
Mast cells/mm^2	—	—	—	22 (15.1–28.9)	16.3 (11–21.7)	0.01
Stained Melanin (%)	—	—	—	8.7 (8–9.5)	6 (5.1–6.9)	<0.001

MASI score was calculated for each treated half-face.
No statistical differences were found in redness (a*) for both treatments, before and after.
Final depigmentation Improvement (L*) did not show differences between both treatments (𝑃=0.78). In parenthesis, confidence Interval to 95%.