What Is Estrogen?

Estrogen acts at various levels in the body and has numerous roles, the most important of which are mentioned here.

• Estrogen is involved in the development of secondary sexual characteristics

  From puberty onwards, the hypothalamus stimulates the pituitary gland, a small gland located at the base of the brain. The secretion of FSH, a follicle-stimulating hormone, and LH, a luteinizing hormone, increases, which stimulates the maturation of the ovarian follicles and thus estrogen production. These act on the mammary gland and are responsible for the anatomical changes that occur during puberty. These include growth of the uterus, change in voice pitch and enlargement of the breasts.

• Estrogens also contribute to the preparation for pregnancy

  Estrogen is also involved in preparing for pregnancy. It builds up the lining of the uterus so that the egg can implant. Just before ovulation, estrogen levels rise, which also leads to a sudden release of LH. This spike in luteinizing hormones triggers the bursting of the follicle containing the egg, and thus the expulsion of the egg through one of the two ovaries into the fallopian tube. After release, the egg travels down the fallopian tube toward the uterus, where it remains for 24 hours, awaiting fertilization.

• Estrogen plays a role in bone growth and development.

  According to several studies, estrogens are thought to have positive effects on bone formation in women and men by inducing the release of extracellular bone matrix proteins and the synthesis of growth factors such as TGF-β3. These, in turn, would be responsible for increased cell proliferation and differentiation. This could also be the reason why bones become more fragile after menopause.

Estrogen is able to stimulate fibroblasts. These are cells in the dermis that are involved in the synthesis of hyaluronic acid, collagen and elastin. Since they are found in the extracellular matrix, all three contribute to the well-being of the skin. Hyaluronic acid is a macromolecule that binds water in the skin, while collagen and elastin give the skin tone and suppleness.

Estrogen thus has a positive effect on the moisture content of the skin. This property has been demonstrated in studies of non-menopausal individuals at various points in the menstrual cycle and during menopause. After menopause and during menstruation, times when estrogen levels are at their lowest, people tend to have sensitive and sometimes dry skin.

Low estrogen levels can be associated with slow renewal of skin cells and impaired skin barrier function. This also promotes the appearance of fine lines and wrinkles, as well as sagging of the skin.