What concentration of azelaic acid is used for acne-prone skin products?

For cosmetic products, a concentration of up to about 14 to 15% by weight is generally used, and published studies indicate azelaic acid remains effective for blemish-prone skin at these levels. For reference, pharmaceutical (drug) products approved by the U.S. FDA for acne are based on 20% azelaic acid creams. Generally, the higher the concentration, the stronger the performance of the product.