While most of us identify estrogen as the female hormone responsible for sex characteristics and reproductive cycles, many of us don’t realize that there are actually three types of naturally occurring estrogens in the body that include, estrone (E1), estradiol (E2), and estriol (E3).

Each of these hormones circulates within the bloodstream at varying levels, depending on the age and stage in a woman’s life.

Estradiol—During the reproductive years, the female body produces higher levels of estradiol than at any other time. This is the strongest of the three estrogens, with a potency 80 times greater than estriol. It is also the most abundant in the non-pregnant years of a woman’s life, between puberty and menopause.

Estriol—When a woman becomes pregnant the estrogen known as, estriol becomes most predominant. While it is the most plentiful of the three major estrogens, it is also the weakest in terms of potency. (Another estrogen hormone, estetrol (E4) is only produced when a woman is pregnant).
Estrone—Once a woman reaches the period of post menopause, the body begins to secrete converted androstendione (a weak androgen steroid hormone) as estrone.

Balanced Estrogen Levels—Supporting Optimal Sexual/Reproductive Function

Estrogen, necessary for sexual and reproductive health plays a critical role in the development of secondary sex characteristics in females as well. Throughout puberty estrogen helps the body develop breasts, pubic hair, and underarm hair.

Produced mainly in a woman’s ovaries, (but also in fat cells and the adrenal gland), estrogen regulates the menstrual cycle by helping the body build the uterine lining necessary for the survival and growth of a fertilized ovum or egg. If the egg does not become fertilized however, estrogen levels sharply decrease and the lining is shed through menstruation.

Progesterone and Estrogen

Once an egg becomes fertilized, estrogen works together with the hormone, progesterone to stop further ovulation. Throughout pregnancy, the placenta, created by the body to support the baby, secretes estrogen in the form of estriol. This hormone further controls the function of lactation in the mother, once the baby is born.

Estrogen—At the Heart of Many Processes

Estrogen is necessary for many other functions and processes within the body as well, including:

• Bone Formation
• Blood Clotting
• Maintenance of healthy skin and hair
• Strengthening and thickening of the vaginal wall
• Strengthening of the urethral lining
• Vaginal lubrication
• Maintenance of flexible pelvic muscles
• Elevation and stabilization of mood

Can the body have too much estrogen?

While estrogen is necessary for the proper function of both sexes, too much estrogen in women, circulating in the bloodstream can present very serious health conditions.

High Estrogen Symptoms

Indicators of high levels of estrogen include:

• Bloating
• Breast tenderness/swelling
• Low libido
• Irregular menstrual cycle
• Frequent headaches
• Changes in mood
• Fibro cysts in the breasts
• Estrogen weight gain, (can’t be attributed to other causes)
• Loss of hair
• Cold feet or hands
• Fatigue
• Memory loss
• Sleep disturbances
• Elevated PMS symptoms

Estrogen provides the fundamental hormones necessary for growth, sexual health, and reproduction in females. Understanding the importance of the different types of naturally occurring estrogens, and the symptoms of too much estrogen within the body is critical in identifying symptoms of a hormonal imbalance, or other hormone related condition.