As a result, there is some controversy about which men should be treated with supplemental testosterone. Although testosterone may make prostate cancer grow, it is not clear that testosterone treatment actually causes cancer. Men taking testosterone replacement must be carefully monitored for prostate cancer. Testosterone may stimulate the prostate gland and prostate cancer to grow. There are times when low testosterone is not such a bad thing. Affected women may experience low libido, reduced bone strength, poor concentration or depression. For example, a man with osteoporosis and low testosterone can increase bone strength and reduce his fracture risk with testosterone replacement. Men who watch sexually explicit films also report increased motivation and competitiveness, and decreased exhaustion. Every mammalian species examined demonstrated a marked increase in a male's testosterone level upon encountering a novel female. Therefore, these mammals may provide a model for studying clinical populations among humans with sexual arousal deficits such as hypoactive sexual desire disorder. Pubertal effects begin to occur when androgen has been higher than normal adult female levels for months or years. On average, in adult males, levels of testosterone are about seven to eight times as great as in adult females. In humans, testosterone plays a key role in the development of male reproductive tissues such as testicles and prostate, as well as promoting secondary sexual characteristics such as increased muscle and bone mass, and the growth of body hair. It also regulates the secretion of luteinising hormone and follicle stimulating hormone. It is used clinically to treat testicular insufficiency, to suppress lactation (milk production), and to treat certain types of breast cancer. It also directs the development of the embryonic Wolffian ducts into the vas deferens (ductus deferens) and seminal vesicles and stimulates the formation of muscle and bone. Free testosterone is in equilibrium with bound testosterone so that when free testosterone enters cells, some bound testosterone is immediately freed. 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. Classical male hypogonadism is when low testosterone levels are due to an underlying medical condition or damage to your testicles, pituitary gland or hypothalamus. As testosterone in your blood increases, it suppresses the production of gonadotropin-releasing hormone, which helps maintain normal levels of testosterone. Total levels of testosterone in the body have been reported as 264 to 916 ng/dL (nanograms per deciliter) in non-obese European and American men age 19 to 39 years, while mean testosterone levels in adult men have been reported as 630 ng/dL. 2020 guidelines from the American College of Physicians support the discussion of testosterone treatment in adult men with age-related low levels of testosterone who have sexual dysfunction. Insufficient levels of testosterone in men may lead to abnormalities including frailty, accumulation of adipose fat tissue within the body, anxiety and depression, sexual performance issues, and bone loss. Any problems with the gonads, hypothalamus, or pituitary gland can cause abnormal levels of testosterone. Other side effects include increased risk of heart problems in older men with poor mobility, according to a 2009 study at Boston Medical Center. It has several possible side effects and some possible long-term effects, as well. The safety of testosterone treatment is still being researched. Another 2017 study published in JAMA found that older men with low testosterone had increased bone strength and density after treatment when compared with a placebo. For instance, it was thought that maybe it would help with age-related memory loss. But sometimes, symptoms of erectile dysfunction are due to other conditions, including diabetes and depression, according to the Mayo Clinic.
