Efficacy on reduction of dark spots
After 28 days of use of Z Luminous Brightening Serum a significant reduction in the size of the treated dark spots was observed (decrease in the mean area of an overage of 7.8%).

Efficacy on skin brightening
After 28 days of use of Z Luminous Brightening Serum had a significant brightening effect on the skin (improvement of an average 9.4% was observed).