Skin Perfecting 2% BHA Gel Exfoliant is a water-based formula that exfoliates both the skin's surface and inside the pore, reshaping the pore lining to unclog pores and improve skin cell turnover rate. This creates a dramatic improvement in the skin's appearance, feel, and function especially for blemish-prone skin. There is a great deal of research indicating that BHA (beta hydroxy acid) increases collagen production and drastically smooths the surface of skin. Additionally, BHA has anti-bacterial properties that attack blemish-causing bacteria. This product is 100% fragrance- and colorant-free with a pH range of 3.2-3.8. Every Paula's Choice BHA product is formulated with additional soothing agents.