How do oral contraceptives affect the menstrual cycle?

Oral contraceptives primarily work by preventing ovulation, which is a crucial aspect of their function. These contraceptives contain hormones, typically a combination of estrogen and progestin, which help regulate the hormonal fluctuations that occur during the menstrual cycle. By maintaining a consistent level of hormones in the body, oral contraceptives can suppress the surge of luteinizing hormone (LH) that triggers ovulation.

Additionally, they change the uterine lining, making it less suitable for implantation if fertilization were to occur, thereby providing an extra layer of contraception. These hormonal changes lead to more predictable menstrual cycles, often reducing menstrual symptoms, and can result in lighter and shorter periods for many users. Overall, the ability of oral contraceptives to prevent ovulation and regulate hormonal levels is fundamental to their role in birth control and menstrual cycle management.