Tighten pores to prevent a recurring cycle of blackheads with the COSRX 2 in One Poreless Power Liquid; a dual-action formula that chemically exfoliates pores with BHA, whilst tightening them with Tannin. Aside from these primary functions, the liquid is effective in cooling down skin temperature & controlling excessive sebum production. Formulated with only 0.1% of BHA, it is suitable for use with other AHA or BHA products.