Estradiol is one of the hormones produced in the body by the ovaries in women. Estradiol levels in the blood are lower in men than women. Because men do not have ovaries, estradiol has no major role in their body. However, estradiol may help to stimulate the production of testosterone by the testes in men.
Estradiol is available in different forms in the market. These include pills, patches, creams and gels. However, many physicians prefer the estradiol injection because it is very effective at increasing testosterone levels. The injections of estradiol are given in the thigh muscles, usually once a month. This form of estradiol therapy is very helpful for men who have very low testosterone levels. This is especially beneficial for men with low testosterone levels and for men who have a prostate condition.
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The role of estradiol (female sex hormone) in the physiology of men is not clear. It is not a hormone in men. In women, its function is to stimulate the development of the female sex characteristics. It has no significant physiological effects in men. However, high doses of estradiol given to men have been shown to increase testosterone levels by stimulating the secretion of luteinizing hormone, which stimulates the Leydig cells in the testes to increase testosterone production. A large randomized study reported in 2015 showed that estradiol given to middle-aged men with low testosterone levels reduced the likelihood of death and other serious health outcomes. The results also show that estradiol use reduces prostate size and also decreases the probability of prostate cancer, especially if the men are overweight.
Estradiol and testosterone in the male body
Both estradiol and testosterone are made from cholesterol. In women, they have different roles in the body. When a woman is not pregnant, estradiol (the female hormone) is produced in the ovaries. It comes to the other tissues of the body (i.e. muscle, liver and fat tissue) through the bloodstream.
Men, on the other hand, do not have ovaries. So they make testosterone, from cholesterol, in the testes. Testosterone is the primary hormone that causes the secondary sex characteristics to develop in boys after puberty and in men after the adolescent growth spurt. It plays a role in muscle and bone growth and in many metabolic activities. It circulates in the bloodstream, then enters all the cells of the body, including those of the brain.
The role of estradiol in women
Estradiol is one of the female sex hormones. In women, it helps regulate the menstrual cycle, the function of the female sex organs, bone growth and other functions in the body. It is made in the ovaries, secreted into the blood, and passes from the bloodstream into the various parts of the body, including the uterus (for women who are pregnant), the breasts and the skin. It is also one of the hormones that control menstrual cycle, pregnancy and growth of the fetus.
The role of estradiol in men
In men, estradiol does not affect their sex characteristics. In fact, women can produce estradiol and have estradiol levels in the bloodstream that are higher than normal men, and this does not cause any noticeable changes. Estrogen plays a role in bone growth, in the development of secondary sex characteristics, in the function of the prostate gland and in several of the functions that occur in the brain.
How estradiol is given to men
In men, estradiol is given in different forms that are designed to keep its level in the bloodstream at the level necessary to maintain health. Some forms are injected and others are tablets.
Hormone replacement therapy in men
The term “hormone replacement therapy” is usually associated with women who are menopausal or have premature menopause. The treatments for these women are called HRT. Although estradiol is mainly used for men, these women do not receive estradiol as a form of hormone replacement therapy.
However, estradiol is the main hormone used for men who have low testosterone levels and who have reduced testosterone production because of age or other medical reasons. It is usually given in the form of a cream. The men take it to increase their testosterone production and to stimulate sperm production.
The use of estradiol and estradiol esters in the treatment of male sexual dysfunction is generally accepted. Research published by Kryscio et al. in the Journal of Sexual Medicine on sexual dysfunction in men shows that the transdermal application of estradiol in doses of 1–1.5 mg/d for 3–5 weeks improved sexual function, increased libido and caused no side effects. In a further publication from the same research group, it is stated that treatment of male sexual dysfunction with a transdermal estradiol patch (Climara®, 1 mg per day) produced similar beneficial effects to those found in the oral treatment of transdermal 17β-estradiol in postmenopausal women.
A limitation in all of the studies mentioned above is the fact that only men with low sexual desire or with problems associated with premature ejaculation were included. A controlled study by Buvat et al. (J Sex Med) shows that there were improvements in quality of life and sexual function in both men and women treated with transdermal estradiol. However, no significant differences in patients with healthy sexual function were found.
The application of testosterone in high doses or in combination with estradiol is an effective means of achieving an increase in libido and an improvement in erectile function in men. It is also used in combination with other hormones or medication (see EPO-Hormonal doping, above).
Estrogen and testosterone in health and disease
There are many conditions that cause changes in the production of testosterone in men. These changes can affect the testosterone levels to such an extent that the levels are either low or very low.
Such conditions may include age, obesity, weight gain, smoking, physical inactivity, lack of exercise, injury, high consumption of alcohol, use of certain medications and medical conditions such as diabetes, stress, etc.
The use of estradiol helps to increase the levels of testosterone. Some studies have shown that it even restores testosterone levels that are too low. Estrogen has also been shown to be effective in maintaining testosterone levels even in older men, who have low testosterone. Estrogen also lowers the chance of prostate cancer by lowering prostate size and lowers the likelihood of death from heart disease.
Why is estradiol in men important?
Because maintaining proper estradiol levels is paramount for sexual health, hormone balance, a normal libido, and a general sense of well-being. Estradiol is a hormone that is responsible for the development of both male and female sex characteristics. By itself, estradiol in men is not required for testosterone to convert to estradiol. This is why you see estradiol in men at very low levels, but high levels of testosterone in both males and females. The major source of estradiol in men comes from testosterone conversion. This conversion starts when testosterone meets the enzyme aromatase, found in the testes, the ovaries, and elsewhere. The conversion continues to occur as testosterone travels to areas of the body outside of the testes and ovaries. These include brain tissue, connective tissue, fat, skin, and hair follicles. When testosterone is converted to estradiol in the skin, fat, and hair follicles, it can remain there until it is cleared by the liver and excreted in urine. Once estradiol leaves the body, it is quickly broken down by the liver and excreted via the kidneys. In men, as in women, estradiol from the body or supplements is quickly taken into the blood and converted to estrone and then estriol. Therefore, if you want to achieve and maintain high levels of testosterone, it is essential that you support the production of estradiol in your body.