Reduction in the appearance of facial hyperpigmentation after use of moisturizers with a combination of topical niacinamide and N-acetyl glucosamine: results of a randomized, double-blind, vehicle-controlled trial.
BACKGROUND
Topical niacinamide and N-acetyl glucosamine (NAG) each individually inhibit epidermal pigmentation in cell culture. In small clinical studies, niacinamide-containing and NAG-containing formulations reduced the appearance of hyperpigmentation.


OBJECTIVE
To assess the effect of a combination of niacinamide and NAG in a topical moisturizing formulation on irregular facial pigmentation, including specific detection of changes in colour features associated with melanin.


METHODS
This was a 10-week, double-blind, vehicle-controlled, full-face, parallel-group clinical study conducted in women aged 40-60 years. After a 2-week washout period, subjects used a daily regimen of either a morning sun protection factor (SPF) 15 sunscreen moisturizing lotion and evening moisturizing cream each containing 4% niacinamide + 2% NAG (test formulation; n = 101) or the SPF 15 lotion and cream vehicles (vehicle control; n = 101). Product-induced changes in apparent pigmentation were assessed by capturing digital photographic images of the women after 0, 4, 6 and 8 weeks of product use and evaluating the images by algorithm-based computer image analysis for coloured spot area fraction, by expert visual grading, and by chromophore-specific image analysis based on noncontact SIAscopy for melanin spot area fraction and melanin chromophore evenness.


RESULTS
By all four measures, the niacinamide + NAG formulation regimen was significantly (P < 0.05) more effective than the vehicle control formulation regimen in reducing the detectable area of facial spots and the appearance of pigmentation.


CONCLUSIONS
A formulation containing the combination of niacinamide + NAG reduced the appearance of irregular pigmentation including hypermelaninization, providing an effect beyond that achieved with SPF 15 sunscreen.
Harvard Medical School, Boston, MA 02114, USA. harvardskinstudies@partners.org
A B
AB
Kimball
J R
JR
Kaczvinsky
J
J
Li
L R
LR
Robinson
P J
PJ
Matts
C A
CA
Berge
K
K
Miyamoto
D L
DL
Bissett
D000117:Acetylglucosamine / Q000008:administration & dosage*; D000287:Administration, Topical; D000328:Adult; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D005145:Face; D005260:Female; D005944:Glucosamine / Q000008:administration & dosage*; D006801:Humans; D017495:Hyperpigmentation / Q000188:drug therapy*; D007091:Image Processing, Computer-Assisted; D008875:Middle Aged; D009536:Niacinamide / Q000008:administration & dosage*; D014677:Pharmaceutical Vehicles; D012880:Skin Pigmentation / Q000187:drug effects*; D013223:Statistics as Topic; D016896:Treatment Outcome
D014677:Pharmaceutical Vehicles; D009536:Niacinamide; D005944:Glucosamine; D000117:Acetylglucosamine