Our iconic global bestseller, this clinically proven daily leave-on liquid exfoliant with salicylic acid quickly unclogs pores and controls oil for clear, glowing skin What is it? BHA (aka salicylic acid) works within the pore lining where congestion, breakouts & blackheads begin. The formula is clinically proven to visibly reduce pores & support the skin barrier for a healthy glow. This leave-on exfoliant (also sometimes known as a toner) has an optimal pH range of 3.2-3.8 for maximum effectiveness without irritation.