adrenaline peptides FAQ

Testosterone plays multiple important roles in the body, such as:

Testosterone is a sex hormone. Hormones are the body's chemical messengers. They travel from one organ or another place in the body, usually through the bloodstream, and affect many different bodily processes. Testosterone is the major sex hormone in males. It is essential to the development of male growth and masculine characteristics. Signals sent from the brain to the pituitary gland at the base of the brain control the production of testosterone in men. The pituitary gland then relays signals to the testes to produce testosterone. A "feedback loop" closely regulates the amount of hormone in the blood. When testosterone levels rise too high, the brain sends signals to the pituitary to reduce production.

Having too much naturally-occurring testosterone is not a common problem among men. That may surprise you given what people might consider obvious evidence of testosterone excess: road rage, fighting among fathers at Little League games, and sexual promiscuity. Part of this may be due to the difficulty defining "normal" testosterone levels and "normal" behavior. Blood levels of testosterone vary dramatically over time and even during the course of a day. In addition, what may seem like a symptom of testosterone excess (see below) may actually be unrelated to this hormone. In fact, most of what we know about abnormally high testosterone levels in men comes from athletes who use anabolic steroids, testosterone, or related hormones to increase muscle mass and athletic performance. Problems associated with artificially high testosterone levels in men include:

In recent years, researchers (and pharmaceutical companies) have focused on the effects of testosterone deficiency, especially among men. In fact, as men age, testosterone levels drop very gradually, about 1% to 2% each year — unlike the relatively rapid drop in estrogen that causes menopause. The testes produces less testosterone, there are fewer signals from the pituitary telling the testes to make testosterone. Also, as men get older, their livers make more sex hormone binding globulin (SHBG), which binds to testosterone circulating in the bloodstream. All of this reduces the active (free) form of testosterone in the body. More than a third of men over age 45 may have reduced levels of testosterone than might be considered normal (though, as mentioned, defining optimal levels of testosterone is tricky and somewhat controversial). Symptoms of testosterone deficiency in adult men include:

Some men and women experience immediate side effects of testosterone treatment, such as acne, disturbed breathing while sleeping, breast swelling or tenderness, or swelling in the ankles. Doctors also watch out for high red blood cell counts, which could increase the risk of clotting. Testosterone therapy does not appear to increase the risk of prostate cancer, but it can stimulate the growth of prostate cancer cells. Because prostate cancer is so common, doctors tend to be leery of prescribing testosterone to men who may be at higher than average risk of having undiagnosed prostate cancer. For men with low blood testosterone levels and symptoms most likely caused by a low level, the benefits of hormone replacement therapy usually outweigh potential risks. However, for most other men it's a shared decision with your doctor.