Yaz is a prescription medication that combines two hormones, ethinyl estradiol and drospirenone, to prevent pregnancy. It is classified as a combination oral contraceptive pill and is taken daily. In addition to preventing ovulation, Yaz can help regulate menstrual cycles and reduce symptoms of premenstrual dysphoric disorder (PMDD). Yaz is typically taken for 28 days, with 24 active pills and 4 placebo pills. It is important for users to follow their healthcare provider's instructions and discuss any potential side effects, such as headaches or mood changes, before starting the medication.