Estrogens: What are they? Related Hormones, Function, Uses and Benefits

They are a group of sex hormones that promote the development and maintenance of female characteristics in the human body.

They play an essential role in the growth and development of secondary female sexual characteristics, such as breasts, pubic and underarm hair, and regulation of the menstrual cycle and reproductive system .

During the menstrual cycle, estrogen produces an adequate environment for the fertilization, implantation and nutrition of an early embryo.

An imbalance of these hormones can lead to a variety of health problems and unwanted physical changes. This article from the MNT Knowledge Center will explain what estrogen is, how it works in the body, its range of medical uses and the effects of estrogen imbalance.

Fast facts about estrogen

The ovaries are the main place for the production of estrogen.

Estrogen influences structural differences between the male and female bodies, such as women who have a wider pelvis and more permanent hair on the head.

Synthetic estrogen has a variety of uses in medicine, including birth control and controlling the effects of menopause .

Estrogen is involved in the development of a variety of health problems.

What is estrogen?

Estrogen is a vital hormone in female development. Hormones are chemical messengers that tell specific tissues to behave in a certain way.

During puberty, the ovaries begin to release estrogen hormones according to each monthly menstrual cycle. The level of estrogen suddenly increases in the middle of the cycle, which triggers the release of an egg. This level then decreases rapidly after ovulation.

Estrogens generally travel through the bloodstream in fluids, interact with cells in a variety of tissues in the body and deliver a message or instruction.

It is one of the most important hormones for women, along with progesterone. Progesterone helps maintain pregnancies and implant an egg in the uterus.

Related hormones in the estrogen family include:

Estrone (E1): this is a weak form of estrogen and the only type found in women after menopause. Small amounts of estrone are present in most tissues of the body, mainly fat and muscle. The body can convert estrone to estradiol and estradiol to estrone.

Estradiol (E2): this is the strongest type of estrogen. Estradiol is a steroid produced by the ovaries. It is believed to contribute to a variety of gynecological problems, such as endometriosis , fibroids and cancers that occur in women, particularly endometrial cancer .

Estriol (E3): This is the weakest estrogen and is a waste product that occurs after the body uses estradiol. Pregnancy is the only time in which significant amounts of estriol are produced. Estriol can not be converted to estradiol or estrone.


Estrogen is crucial for the reproductive function and cycle of a woman.


In women, estrogen affects the following areas of the body:

Ovaries: Estrogen helps stimulate the growth of an egg follicle.

Vagina: also stimulates the growth of the vagina to its adult size, the thickening of the vaginal wall and an increase in vaginal acidity that reduces bacterial infections. It also helps to lubricate the vagina.

Fallopian tubes: Estrogen is responsible for the growth of a thick, muscular wall in the fallopian tubes, and the contractions that carry the ovum and sperm cells.

Uterus: estrogen enhances and maintains the mucous membrane that lines the uterus. It increases the size of the endometrium and improves blood flow, protein content and enzymatic activity.

Estrogen also stimulates the muscles of the uterus to develop and contract. The contractions help during the birth of a baby and the placenta, and also help the wall of the uterus to eliminate dead tissue during menstruation.


It is believed that estrogen regulates the flow and thickness of uterine mucous secretions. This improves the movement of a sperm to an egg and allows fertilization.

Mammary glands:

Estrogen forms unique relationships with other hormones in the breast. They are responsible for the growth of the breasts during adolescence, the pigmentation of the nipples and, finally, stop the flow of milk when a baby is no longer breastfeeding.

Estrogen is responsible for the differences between the male and female bodies. For example, in a female body:

  • Estrogen causes the bones to be smaller and shorter, the pelvis wider and the shoulders narrower.
  • It increases the storage of fat around the hips and thighs, which means that the body is more curved and contoured.
  • Estrogen helps slow down the growth of females during puberty and increases insulin sensitivity. Insulin influences the amount of body fat and lean muscle a person can develop.
  • It influences body hair to become thinner and less pronounced, while making hair on a woman’s head more permanent.
  • Estrogen causes the voice box to be smaller and the vocal cords shorter, giving the females a sharper voice than the males.
  • Estrogens suppress the activity of glands in the skin that produce oily substances. This reduces the likelihood of acne in women.

Other areas in which estrogen has an impact include:

The brain: can help maintain body temperature, regulate the part of the brain related to sexual development and improve the effects of chemicals that “make the brain feel good”.

The skin: estrogens improve the thickness and quality of the skin, as well as the collagen content that prevents aging.

Bones: Estrogen helps preserve bone strength and prevent bone loss.

The liver and the heart: the hormone regulates the production of cholesterol in the liver, which helps protect the heart and arteries.


Some foods contain phytoestrogens, which can affect the levels of estrogen in the body.

These include:

  • Cruciferous vegetables.
  • Soy and some foods that contain soy protein, the most concentrated source.
  • Berries
  • Seeds and grains
  • Nuts
  • Fruit.
  • Came.

Some scientists believe that phytoestrogens are endocrine disruptors. They seem to have dual functions at times, capable of increasing and decreasing the activity of estrogen.

It is a common misconception that phytoestrogens can adversely affect health, but some research confirms that foods that contain phytoestrogens mentioned above can reduce cancer risk, reduce hot flashes, improve other menopausal symptoms, and provide other health benefits. .

The effects of soy phytoestrogens depend on the type of soybean that is being studied at the time, and this has led to inconsistent results. The soy protein isolate will have a different impact than whole soy foods.


Synthetic estrogen, bioidentical estrogen and estrogens derived from pregnant mares are used for a variety of medical purposes.

The most common uses of estrogen are contraceptive pills and hormone replacement therapy (HRT) and bioidentical hormone replacement therapy (HBOT) for menopause.

Pill of the day after:

The contraceptive pill is the method of birth control most commonly used in the United States. Estrogen is included in combined oral contraceptive pills along with the hormone progestin.

Many women take low-dose birth control pills, which contain 20 to 50 micrograms (mcg) of estrogen.

Estrogen in the combined pill sends comments to the brain. This feedback causes a variety of effects on the body, including:

  • Stop the pituitary gland so it does not secrete follicle-stimulating hormone (FSH).
  • Stop the production of luteinizing hormone (HL).
  • Prevent ovulation
  • Supporting the lining of the uterus to prevent intermenstrual bleeding that can sometimes cause spotting between periods.

Some doctors may prescribe contraceptives for alternative uses, which include:

  • Regulating the menstrual cycle.
  • Relieving severe cramping and heavy bleeding.
  • Reduce the risk of ovarian cancer and the development of ovarian cysts.
  • Protection against ectopic pregnancy.
  • Decrease in perimenopausal symptoms.
  • Helping reduce the severity of acne related to hormones.

Taking a contraceptive pill carries a number of risks, such as:

  • Heart attack.
  • Blood clots.
  • Pulmonary embolism .
  • Nausea and vomiting.
  • Headaches.
  • Irregular bleeding
  • Weight changes
  • Sensitivity and swelling in the breasts.
  • Long-term use can also lead to an increased risk of breast cancer ..

Hormone replacement therapy:

Hormone replacement therapy (HRT) aims to relieve some symptoms of menopause by making female hormone levels return to normal. The treatment can be provided as estrogen alone or as a combination of estrogen and progestin.

For women who still have a uterus, the hormone progestin is used along with estrogen to prevent overgrowth of the lining of the uterus, which can lead to endometrial cancer. HRT is available in the form of a pill, nasal spray, patch, skin gel, injection, vaginal cream or ring.

HRT can help relieve symptoms of menopause, such as:

  • Hot flushes.
  • Vaginal dryness
  • Painful copulation.
  • Humor changes.
  • Sleep disorders.
  • Anxiety .
  • Decrease in sexual desire

The US Food and Drug Administration (FDA) UU Recommends that HRT be used in the lowest doses for the shortest time necessary to achieve the treatment objectives.

This may help to avoid some of the uncomfortable side effects, such as:

  • Swelling.
  • Chest pain.
  • Headaches.
  • Humor changes.
  • Nausea.
  • Retention of liquid.

Women who use or are considering the use of hormone therapy after menopause should discuss the possible health benefits and risks with their doctors.

Hormone therapy is also used to help transgender people who want to transition between sexes, and estrogen is often prescribed to help transgender women who seek to develop female secondary sex characteristics.

Due to the risks posed by this type of therapy, it is vital that a course of hormonal therapy be followed under the supervision of a medical professional.