Total Testosterone Total Testosterone That study showed that a baseline T level of less than 200 ng/dL is linked to greater increases in spine BMD. A BMD test helps clinicians detect osteoporosis and predict risk for bone fractures. A new study finds that an increase in the male hormone testosterone helps to improve body composition, even in men with testosterone levels near the lower end of normal. Testosterone therapy is used mostly by aging men with low testosterone levels but is exploited by others looking to stop the normal testosterone decline that’s part of male aging. (Photo for illustrative purposes only. © Getty Images/Nastasic). As men age, both their testosterone levels and muscle mass naturally start to decline. Some men may start noticing symptoms of reduced testosterone, such as hair loss or fatigue. By the time they reach 15 to 16 years old, teen boys typically have a testosterone level of 100 to 1,200 ng/dL. Doctors will have to start at the beginning, with small, short-term trials of testosterone in older men. If the benefits appear to outweigh the risks, the next step will be larger, longer trials in younger men. Only then will men know if testosterone therapy is effective or safe. Until recently, men who needed testosterone required injections of the hormone every one to three weeks. Now, most men use skin patches (Testoderm, Androderm), gels (AndroGel, Testim), or tablets that are placed on the surface of the gum, where they form a gel that releases the hormone so it can be absorbed across the mouth’s membranes (Striant). 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. Females experience a more dramatic change in hormones, with levels falling until they reach menopause, while males experience a more gradual change in hormone levels. Adult males typically have between 265 and 923 nanograms per deciliter of testosterone (ng/dL) in their blood, while adult females have far less. These include medicine side effects, thyroid problems, or depression. Beginning around age 30 to 40, testosterone levels may start to slowly decrease. These tests should be conducted in the morning (typically between 7 a.m. and 9 a.m.) when testosterone levels are at their peak. High testosterone in males can cause a variety of signs and symptoms, including acne, increased sex drive, excessive facial and body hair, mood changes, infertility, and more. For example, athletes and bodybuilders sometimes use anabolic steroids to improve athletic performance and build muscle mass. This can lead to symptoms of high testosterone levels, and doctors may recommend stopping taking steroids. If your testosterone levels are higher or lower than normal, you may have a condition that affects your testosterone production. If your levels are higher than normal, you may have a tumor on the testes or ovaries.