Progesterone is a steroid hormone essential for regulating the menstrual cycle, maintaining pregnancy, and supporting various functions within the reproductive system. Produced mainly by the corpus luteum in the ovaries after ovulation and, during pregnancy, by the placenta, progesterone prepares the endometrium (the uterine lining) for a potential pregnancy. If fertilization occurs, progesterone supports the early stages of pregnancy by maintaining the endometrial lining and preventing uterine contractions.

In addition to its crucial role in reproduction, progesterone balances the effects of estrogen and helps regulate the menstrual cycle. During the luteal phase of the cycle, progesterone levels rise, leading to the thickening of the endometrial lining. If pregnancy does not occur, progesterone levels fall, triggering menstruation.

Progesterone is also involved in several other physiological processes. It has a calming effect on the brain, contributing to mood regulation and reducing anxiety. It plays a role in bone health by promoting bone formation and reducing bone resorption. Additionally, progesterone helps maintain cardiovascular health by relaxing blood vessels and contributing to the regulation of blood pressure.

Abnormal progesterone levels can lead to various health issues. Low progesterone can result in irregular menstrual cycles, difficulty maintaining pregnancy, and symptoms of premenstrual syndrome (PMS) such as mood swings and bloating. High levels of progesterone can cause fatigue, mood changes, and breast tenderness.

Progesterone therapy, available in forms such as pills, creams, and injections, is often used to address hormonal imbalances, support fertility treatments, and alleviate menopausal symptoms. However, like any hormone therapy, it should be administered under medical supervision to manage potential side effects and ensure appropriate dosing.