This powerful extra strength formulation has been especially developed to address the problem of very dark resistant hyperpigmentationdioic acid derivative is a powerful inhibitor of melanin production penetrates deeply through the epidermal skin layer giving better faster results in addition the powerful azelaic acid phytic acid salicylic acid bleach and exfoliate the skin stronger formulation with sun protection factor spf15 is included we recommend using sun blockex spf 50 for