Duac once daily Gel is a powerful anti-acne treatment effective against bacteria that cause scarring whiteheads and blackheads on the skin. It is mainly used for mild acne. The condition occurs due to the blocking of pores caused by excess sebum. Once blocked, the skin forms spots and pimples. If bacteria infects the areas, the skin gets acne. Duac Gel targets the pimples and prevents new impurities on the skin.