Key ingredients: kojic acid, niacinamide ... Leave it on for at least six hours every two or three days. Why we love it: Murad Rapid Dark Spot Correcting Serum stepped in as the hydroquinone ...

Ascorbic acid sulfate and ascorbyl palmitate are other forms of vitamin C used in skin products like serums and creams. 2. Kojic Acid What it does: Kojic acid is a byproduct of the fermentation of ...