What hormones are involved in the menstrual cycle?

The hormones involved in the menstrual cycle are oestrogen, progesterone, follicle-stimulating hormone (FSH), and luteinising hormone (LH).

The menstrual cycle is a complex process regulated by a series of hormones. The first hormone involved is the follicle-stimulating hormone (FSH), which is released by the pituitary gland at the start of the cycle. FSH stimulates the growth of follicles in the ovaries, each containing an egg. As the follicles grow, they start to produce oestrogen.

Oestrogen is the second hormone involved in the menstrual cycle. It is produced by the ovaries and has several roles. Firstly, it stimulates the lining of the uterus to thicken in preparation for a potential pregnancy. Secondly, it inhibits the release of FSH to prevent more than one egg from maturing in a cycle. Lastly, a surge in oestrogen triggers the release of another hormone, luteinising hormone (LH).

Luteinising hormone (LH) is responsible for triggering ovulation, the release of the mature egg from the follicle. This usually occurs around the middle of the menstrual cycle. After ovulation, the follicle transforms into a structure called the corpus luteum, which begins to produce progesterone.

Progesterone is the final hormone involved in the menstrual cycle. It further prepares the uterus for a potential pregnancy by maintaining the thickened lining. If fertilisation does not occur, the levels of progesterone drop, causing the lining of the uterus to break down and be shed in what is known as menstruation. This marks the start of a new menstrual cycle.

In summary, the menstrual cycle is a carefully coordinated process involving the interplay of four key hormones: FSH, oestrogen, LH, and progesterone. Each hormone has a specific role in preparing the body for a potential pregnancy and in regulating the cycle.