Dear Dr. Sami AL-Maliki

  Estrogen is the primary female sex hormone which gives them what they need in order to be a women. Men on the other hand gets testosterone. If a man starts to take estrogen through long term use, will have a sexual change in themselves. Large muscle group typically found in men will continue to shrink making the person less manly. Basically you become weaker and will even grow breast. Things like facial hair or body hair may start to grow out a lot slower.

THANK YOU

Dear Sami,

Testosterone is the dominant sex hormone in males, and high levels of testosterone are needed for normal development of male secondary characteristics and normal function of male reproductive tract.

Men do also have circulating estrogens, but normally in low levels. This low levels of estrogen in men come from the aromatization of androgens (testosterone) in testes (Leydig cells), adrenal cortex, brain, liver, muscle tissue and especially adipose tissue. This is why obese men have higher estrogen levels than non-obese men. 

Excluding exposure to exogenous estrogen, men can get higher estrogen levels in some pathological conditions, such are : aromatase excess syndrome (a genetic endocrine syndrome characterized by over-expression of enzyme aromatase, that is responsible for conversion of androgens into estrogens), some type of adrenal tumors that produce high levels of estrogen, liver cirrhosis, severe obesity etc. Also aging (due to increase in aromatase activity) and testosterone therapy can cause high estrogen levels in men.

Increased levels of estrogens in men cause:

• enlarged breasts (gynecomastia, which is the most common symptom).
• sexual dysfunction (low libido, decreased erectile function).
• fertility problems.
• loss of muscle mass
• emotional disturbances, especially depression.
• benign prostatic hyperplasia and increased risk for prostate cancer.
• type 2 diabetes (different from females, in males high estrogen causes increased abdominal fat, which increases the insulin resistance and risk for type 2 diabetes). 

Estrogens are not present only in women - men have physiological smaller (approximately a half) circulating estrogens, to which we must add the estrogens resulting from the aromatase action. They are active through estrogen receptors (ER), which are ubiquitary. ER response is the same irrespective of the origin of the estrogens. So any estrogen excess, relative (as in eldery men, were there is a decline in androgen levels) or absolute (endogenous or exogenous hyperestrogenism) in men will induce estrogen effects like breast enlargement, testicular and prostatic atrophy, diminished libido, erectile disfunction, as well as feminizing features (thin skin, loss of androgenic hair, thin voice, etc)