Hormones and menstruation: what happens during the menstrual cycle?

The menstrual cycle is directly linked to hormonal variations. Hormones influence the cycle and menstruation throughout the cycle and every day thereafter. They guarantee the proper functioning of the reproductive system.

What hormones are involved in menstruation and the menstrual cycle?

The release of hormones is totally natural, but also synonymous with the onset of menstrual disorders. Every month, a small organ in the brain produces afollicle-stimulating hormone and a luteinizing hormone to trigger ovulation. The ovaries, in turn, produce more substances such as progesterone and estrogen to produce an egg and stimulate the uterus to accommodate a potential pregnancy.


At puberty, estrogen is responsible for the development of the female genitalia, and plays a role in :

  • the uterus and thickening of the uterine lining
  • breast growth
  • the brain
  • skin and hair quality
  • fat and cellulite development
  • oocyte production

Estrogen acts at the start of the cycle and until the end of ovulation. This hormone is secreted by FSH, thefollicle-stimulating hormone, which stimulates the development of a certain number of follicles. During the first few days of menstruation, estrogen levels are at their lowest and begin to rise as FSH increases and follicles develop in the ovaries. When estrogen levels are highest in the blood, you may notice cervical mucus, a clearer, more viscous white discharge.


The follicles then begin to produce a new hormone called progesterone. Progesterone is a hormone that strengthens theendometrium to support an embryo. Throughout the process, the unfertilized follicle will begin to break down and continue to produce progesterone as well as estrogen. This hormone will have an impact on periods and, in particular, premenstrual syndrome. Various symptoms may appear at first, such as breast pain, bloating and mood swings. If these are too severe, it's important to consult your health care professional or gynecologist.

How do hormones affect the menstrual cycle?

Hormonal variations affect the length of menstrual cycles, as well as the symptoms present in the body. On average, a woman's cycle repeats itself and lasts 28 days. Hormones will intervene in a rhythmic way, reproducing themselves on a monthly basis!

From the first day of menstruation to ovulation

There are two phases, from the first day of menstruation to the production of an egg by each ovary. Menstrual hormones are not yet present, but estrogens cause theendometrium to thicken. Throughout this phase, the ovarian system is preparing to ovulate. The luteinizing hormone LH then releases an oocyte, which migrates through the fallopian tubes towards the uterus.

From ovulation to the first day of the new menstrual cycle

From halfway through the previous bleeding cycle to the first day of the new cycle, hormone production activates progesterone. This is known as the luteal phase (or progesterone phase). During this phase, the empty follicle transforms into a corpus luteum, which secretes progesterone to stimulate the uterine lining. At the end of this phase, if there has been no fertilization, the uterus will detach and evacuate through the vaginal tract. It's back to menstruation and a new cycle!

How do hormones affect the body during menstruation?

Hormones not only affect the menstrual process, they also have an impact on the symptoms, libido and physiological changes experienced by menstruating women. Hormonal variations will trigger symptoms that are more or less easy for women to cope with, right up to the menopause. Hormones are notorious for their effects on :

  • libido
  • digestive system
  • breast size and sensitivity
  • mood

Increased libido

From a hormonal point of view, as we approach the ovulatory period, estrogen levels rise and libido increases. The peak of the estrogenic hormone occurs at the moment when a woman is most ready to get pregnant. Once each ovary has done its job, progesterone reduces libido. Sexual desire then subsides, particularly with the onset of premenstrual syndrome and its associated symptoms. As soon as menstrual bleeding starts, the menstrual hormones gradually boost libido. During menstruation, it's perfectly possible to have sex, especially as pleasure releases endorphins that calm the symptoms of menstrual pain!

Menstrual problems

Hormonal variations have an impact on menstrual disorders in women. In fact, a heavy load of hormones has an impact on the development ofendometriosis and polycystic ovary syndrome, for example. Hormonal disorders linked to the menstrual period are frequently observed and can be the cause of psychological and physical discomfort. Menstrual flow can also be :

  • painful (dysmenorrhea)
  • abundant and long (menorrhagia)
  • irregular or absent (amenorrhea)

Hormones during menstrual flow and the cycle play a decisive role.

A physiological change

In fact, under the influence of hormonal variations, a woman's reproductive system evolves in several phases and repeats itself over time. Hormones play a natural role in these physiological changes. Do not hesitate to consult a doctor or gynaecologist if these physiological changes are too restrictive.

FAQs on hormones and menstruation

How do hormones affect menstruation?

Hormones play a decisive role in menstrual flow. Hormonal variations are involved in all phases before, after and during menstruation. They trigger blood flow, the ovarian system and the expulsion of the corpus luteum. In addition to a direct link with the onset of menstruation, hormones also trigger important physical and psychological symptoms.

Which hormones decrease during menstruation?

When a new menstrual cycle begins, menstruation kicks in. Two substances are at their lowest: estrogen and progesterone. They trigger menstrual bleeding and menstruation-related symptoms such as stomachaches and menstrual migraines.

You may also like :