[Product Question] Is it recommended to use Vitamin C and Azelaic Acid together?

Beauty Tips For Body Care
I’m trying to treat my PIE, and have not seen any results from Niacinamide, so I’m thinking of trying Azelaic Acid. Is it fine to use with my TO Vitamin C (23%) or will that be too harsh?
Girls Blog 2015
Submitted by partypotatoes