DDF is developed by Dr. Howard Sobel, MD is considered a powerful over the counter wash w/ 5% glycolic to exfoliate dead skin cells & assist in cell turnover. The second step consist of the glycolic toning complex, which is used with a cotton pad. The toning complex is pH balanced for the skin. As a master esthetician, I considered this two system very powerful. Just follow through w/ a good skin serum. DDF will not disappoint. No trades, no returns, same or next day shipping.Trusted seller