If you damaged your skin like me by mixing Vitamin C and niacinamide and went out in the sun with no sunscreen, this will help you, and its fast, but you have to apply it twice a day and be generous but maybe not too too much, the results can be shown fast, i got some redness on maybe the first 20 min or smth, also i applied it 3 times so far, one of these times i had a heating sensation in my face , whiped some of it out and turned on the AC to really cold, woke up after a few hrs and my skin was looking amazing, also if u see some darkness the first 20-30 min its fine or atleast in my situation, when u wash it off u will look great, this is whag happened to me atleast.