According to MedlinePlus, benzoyl peroxide is one of the best substances to treat mild to moderate acne. It is an organic compound and is contained in most over-the-counter products, including lotions, creams or sprays. Many specialists consider it an effective treatment and can produce results in four to six weeks. For more severe cases of acne or scarring, a doctor may recommend a prescription medicine such as Accutane or make a referral to a cosmetic clinic.