Effective blemish treatment works by reducing oil production, eliminating skin-cell buildup on the surface of skin and in the pore, and killing the bacteria, P, acnes, that caused the inflammation in the first place. That’s why the best course of action for blemishes is twofold, both topical (what you put on the skin, whether it’s an over-the-counter or a prescription option) and systemic (prescription oral medication that addresses the issue of oil production and bacterial growth).