The role of estrogen

Estrogens are the best-known female sex hormones. Estrogens not only regulate reproductive function, but also influence many other areas of the body.

Estrogen" itself is a generic term. In fact, the term covers over 30 different estrogen hormones, the main ones being estradiol, estrone and estriol.

• along with progesterone (hormone of the corpus luteum), it is one of the main female sex hormones
• the ratio of estradiol to progesterone is essential for sexual differentiation, regulation of the menstrual cycle and the onset or maintenance of pregnancy
• in women, daily estradiol production increases during the first half of the cycle, particularly in the ovaries (from 70-150 µg to 200-400 µg), triggering ovulation
• after ovulation, estradiol secretion returns to its usual daily level, which is the level of the second half of the cycle,
  i.e. 150-300 µg
• with the perimenopause, estradiol production declines steadily and gradually comes to a halt with the menopause, which is the time of the last menstrual period and the extinction of ovarian function
• in early postmenopause (1 year after the last menstrual period), only very small quantities of estradiol (5-25 µg per day) are still produced, mainly in the adrenal cortex and adipose tissue

• is less effective, but is the second most potent estrogen in women after estradiol
• can be converted into estradiol, and is therefore primarily a storage form of estradiol
• most of it is produced in the ovaries, like estradiol; a further 20% to 30% in adipose tissue and the adrenal cortex
• if the estradiol/estrone ratio is still 2:1 before menopause, this ratio reverses in post-menopause with the cessation of ovarian activity to reach a ratio of around 1:2. At this stage of life, estrone is produced almost exclusively in subcutaneous adipose tissue.

• is a weakly active estrogen which is mainly produced by the placenta during pregnancy, and is therefore often referred to as pregnancy estrogen.
• Estriol is nevertheless often used topically in the form of vaginal creams, suppositories or tablets, e.g. in cases of inflammatory changes of the vaginal skin with tissue atrophy during and after the menopause.

During the menopause, the level of estradiol produced by the body decreases continuously until the last menstrual period (menopause). The lack of estradiol is a key factor in disorders, especially after the menopause (post-menopause).

Women often experience problems as early as the perimenopause. Estradiol is still produced and menstruation still occurs, albeit with increasing irregularity.

It is assumed that this is triggered by sharp fluctuations in both estradiol and progesterone levels. In effect, the ovaries are less and less active, with estrogen and progesterone secretion continually declining. During this phase, the body tries to compensate by increasing the brain's secretion of the hormones FSH (follicle-stimulating hormone) and LH (luteinizing hormone). The ovaries are thus stimulated to produce hormones. As progesterone levels are already very low, estradiol levels sometimes rise sharply, leading to problems such as breast tension and pain. If high estradiol levels fall again with the onset of menstruation, this can be accompanied by hot flushes and more frequent sweating.

However, not all menopausal women experience a drop in estrogen levels. In fact, around 20% of women go through menopause without menopause-related symptoms, while the other 80% suffer from mild to severe disorders. 1

Among other things, hormonal fluctuations unbalance the vegetative nervous system. This controls unconscious bodily functions such as heart rate, breathing and metabolism.

This imbalance leads to the most characteristic, frequent and distressing symptoms of menopause:

• hot flushes
• sweating
• tachycardia
• dizziness
• constipation

• sleep disorders
• depressive moods, even depression
• panic attacks/anxiety disorders
• inner restlessness and irritability

Estrogen deficiency can cause symptoms such as

• increased pH in the vagina, which can lead to burning and itching
• disturbed vaginal flora, which facilitates the entry of germs and can therefore lead to an increase in urinary tract infections
• limited functionality of the mucous membranes, leading to incontinence problems

The reduced effect of estrogen also influences collagen formation, blood circulation and fluid supply in the joints. This can have the following effects

• increased joint stiffness
• suppression of certain anti-inflammatory and analgesic effects of estrogen, which can lead to joint pain

The body's reduced production of estradiol can lead to a reduced protective effect against various diseases during the menopause. In women over 50, the risk of developing diseases increases:

• osteoporosis and osteoporosis-related fractures, as bone resorption outweighs bone formation
• arteriosclerosis, as the positive effect of estrogen on blood vessels, inflammatory reactions and blood pressure no longer exists
• myocardial infarction and stroke due to arteriosclerotic changes in blood vessels
• dementia: a link with estrogen deficiency is suspected here, not least because estrogen's protective influence on neurons and its regulatory effect on the brain's energy supply diminish.