Testosterone is a hormone that is present in both men and women. Testosterone is the androgenic hormone primarily responsible for normal growth and development of male sex and reproductive organs, including the penis, testicles, scrotum, prostate, and seminal vesicles. It facilitates the development of secondary male sex characteristics such as musculature, bone mass, fat distribution, hair patterns, laryngeal enlargement, and vocal chord thickening. Additionally, normal testosterone levels maintain energy level, healthy mood, fertility, and sexual desire.
Men have 10 to 20 times higher levels of testosterone than women. Nonetheless, even this small amount of testosterone in women is important for maintaining sexual function, and healthy bladder and vaginal function. There are no commercially available testosterone preparations for women. Therefore testosterone preparations for women are usually custom-made by a compounding pharmacist. When used in small physiologic doses with monitoring of testosterone blood levels, testosterone in women is well tolerated. High doses must be avoided as they can cause facial hair, loss of scalp hair and acne.
Testosterone replacement is essential for men with hypogonadism either from surgical removal or dysfunction of the testicles. In these men, full replacement of testosterone is necessary. The range of total testosterone in men can range from 300 to 1000 ng/ml and for free testosterone, the range is 50 to 250 ng/ml. It is generally more accurate to utilize free testosterone levels instead of total.
Because the range is so broad, it is often difficult to determine exactly what level is best for a given individual. In general, we aim to provide the lowest dose of testosterone that relieves symptoms and causes the man to be in the low to mid-normal range. In certain individuals, higher levels are necessary but this should be done by an experienced physician who is monitoring testosterone and estradiol levels.
It is very important to emphasize that more is not necessarily better. For example, if a man’s “normal” level is closer to 500 and he increases it to 1000 with excessive testosterone replacement, he may temporarily feel good short-term. However, such long-term excessive doses are often associated with irritability and uncontrolled angry outbursts. Furthermore, excessive testosterone replacement results in increased conversion to the female hormone, estrogen, which is very harmful to a man. Increased estrogen levels in men have been implicated in some cases of prostate cancer. In addition, increased estrogen can result in breast formation called gynecomastia which is most bothersome to men. Excessive levels of testosterone can also cause lowering of cholesterol, increased red cell count leading to hypertension and increased heart disease. Excessive testosterone can also cause an increased reddening of the skin, which resembles mild sunburn.
It is also important to note that men should not be started on testosterone replacement without a careful endocrine evaluation to determine the cause of the low testosterone. Serious conditions including pituitary tumors can present with low testosterone.
√ - July 1st - National Fox Business Health News - Writer Barbara Mannino publishes health article "The Low Down on Low-T; Replacement Can Help" assisted by Dr. Marina Johnson - Click to Read Article