What is the primary function of oral contraceptives?

The primary function of oral contraceptives is to prevent ovulation. These hormonal medications work primarily by inhibiting the release of eggs from the ovaries, which is crucial for preventing pregnancy. By maintaining consistent hormone levels through the administration of estrogen and progestin (or progestin-only in some formulations), oral contraceptives effectively suppress the hypothalamic-pituitary-ovarian axis needed for ovulation to occur.

In addition to preventing ovulation, oral contraceptives also influence the uterine lining, making it less hospitable for potential implantation of a fertilized egg, and thicken cervical mucus, which impedes sperm movement. However, the key mechanism that defines their contraceptive action is ovulation suppression.

While oral contraceptives can have secondary benefits, such as regulating menstrual cycles and addressing conditions like polycystic ovary syndrome (PCOS), these effects are not their primary purpose. They do not enhance fertility; rather, they are designed to prevent it, making the primary function of oral contraceptives clear.