Azelaic acid 20%, ascorbic acid 15%, kojic acid 4%, retin a 0.1, hydrocort to treat post-inflammatory pigment. (photo)

I was prescribed the combination of ( azelaic acid 20% , ascorbic acid 15% , kojic acid 4% , retin a 0.1 , hydrocort ) , i was using the combination for three hours a day for two months straight and then i stopped , and i noticed some whitening of the skin surrounding the red marks i want to get rid of ,, should i restart the same treatment and leave it for more than three hours to notice more notable difference ?! And to make it more effective ?! , BTW my skin isn't sensitive or anything

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