Which hormone is primarily responsible for regulating the female menstrual cycle?

The female menstrual cycle is primarily regulated by the hormones estrogen and progesterone. These two hormones play crucial roles in the various phases of the menstrual cycle.

At the beginning of the cycle, estrogen is released from the developing follicles in the ovaries, which promotes the thickening of the endometrial lining in preparation for a potential pregnancy. As the cycle progresses and ovulation occurs, a spike in luteinizing hormone triggers the release of the egg, and progesterone levels start to rise, further preparing the endometrium for implantation. If pregnancy does not occur, progesterone levels fall, leading to the shedding of the endometrial lining, which is experienced as menstruation.

In contrast, other hormones listed do not play the same direct regulatory roles in the menstrual cycle. Testosterone is primarily associated with male characteristics and reproductive functions, insulin is crucial for glucose metabolism, and cortisol is a stress hormone that affects various bodily functions, including metabolism and immune response, but is not directly involved in the regulation of the menstrual cycle.