Why use Salicylic Acid? Salicylic Acid not only treats adult cystic acne but it builds collagen. This article answers What Is Salicylic Acid and how to eliminate blackheads Salicylic Acid treats adult acne and builds collagen Salicylic Acid is an ideal acne treatment for skin over 30, it purges pores of acne-causing contents, fights…