US Pharm. 2021;46(6):15-16.

Testosterone is a primary hormone produced in the testicles and is essential for male reproductive and sexual function, metabolism, body composition, and mental processes. Low testosterone is marked by a blood level below the standard expected range. It is caused by hypogonadism, a condition in which the testicles do not make enough testosterone. Hypogonadism can occur at any age, often as a result of infection or testicular injury. It may also be due to a problem with the pituitary gland, which stimulates the testicles to make testosterone under normal circumstances. Signs and symptoms of hypogonadism differ depending on the point in life that the condition develops.

Testosterone Levels Influence Development and Vitality

Testosterone is responsible for developing masculine physical traits, including muscle mass and strength, sperm production, sex drive, bone strength, and red blood–cell production. Typically, testosterone levels rise during puberty, peak around age 30 years, and slowly decline with age. It is not abnormal for testosterone to drop below the normal range once a man reaches age 70 years or older.

During fetal development, testosterone influences the development of external sex organs. Low testosterone during fetal development can result in the expression of female genitalia or underdevelopment of male genitalia. Low testosterone levels during adolescence can interrupt puberty. In adulthood, reductions in circulating testosterone impact fertility, sex drive, energy levels, and bone strength. Not all low testosterone levels are symptomatic.

Complications of Low Testosterone

Several other conditions can cause testosterone to fall below normal levels, including other hormone imbalances, testicular cancer or cancer treatment, genetic factors, infection, injury to the testicles, obesity, type 2 diabetes, heavy alcohol use, liver disease, and HIV/AIDS. Drugs such as spironolactone, digoxin, and steroids can decrease testosterone.

To prevent the complication of delayed puberty in boys, early detection of hypogonadism is essential. Identifying and treating low testosterone levels can preclude complications such as osteoporosis and loss of strength in men. In males with symptoms of low testosterone, physicians can check for testosterone levels using common blood tests, taken at several points in time.

Many Testosterone Formulations Available

If an otherwise healthy young male presents with low testosterone levels, the underlying cause can be addressed (such as obesity or infection), and testosterone-replacement therapy may be prescribed. However, he should avoid testosterone-replacement therapy if conception is an issue, as it can inhibit sperm production.

The FDA has approved new oral testosterone medications to treat particular conditions that result in hypogonadism, including Klinefelter syndrome or pituitary tumors. These medications are not approved for use in men with low testosterone due to aging. Many other dosage forms of testosterone-replacement therapy are available. For example, testosterone may be given by injection every few weeks or via the skin using a patch, gel, or solution applied every day. Testosterone is also available in tablet form, known as a buccal tablet, that is placed on the front upper gum under the lip and releases over 12 hours. Finally, testosterone-replacement therapy can be administered using implants under the skin that slowly release testosterone over 3 to 6 months.

Balancing the Risks Versus Benefits of Treatment

The side effects of testosterone-replacement therapy include enlarged breasts, enlarged prostate, acne, and increased red blood–cell production. Men with prostate cancer are usually not candidates for testosterone therapy, and men with breast cancer should not receive testosterone. The solution and gel formulations must be thoroughly washed from the hands to avoid skin-to-skin contact and transfer to others.

Since testosterone levels naturally decline with age, the decision to manage low testosterone levels with hormone-replacement therapy must be considered on an individual basis by fully exploring the risks and the benefits of treatment. There is no clinical evidence that testosterone supplementation has a positive effect in men with normal testosterone levels.

The use and promotion of herbal testosterone supplements or stimulants have skyrocketed in recent years. However, these products have not been studied carefully for safety or effectiveness.

The content contained in this article is for informational purposes only. The content is not intended to be a substitute for professional advice. Reliance on any information provided in this article is solely at your own risk.