Testosterone is a hormone produced by the testicles and is responsible for the proper development of male sexual characteristics. Testosterone is also important for maintaining muscle bulk, adequate levels of red blood cells, bone density, sense of well-being, and sexual and reproductive function. Once it is produced, the hormone is regulated by the pituitary gland. Contrary to what some people believe, testosterone isn’t exclusively a male hormone. Women produce small amounts of it in their bodies as well.
As men age, their testes often produce somewhat less testosterone than they did during adolescence and early adulthood. But it is important to keep in mind that the range of normal testosterone production is vast. So while there are some declines in testosterone production with age, most older men stay well within normal limits.
By the time men are between the ages of 40 and 55, they can experience a phenomenon similar to the female menopause, called andropause. Andropause is a condition supposedly caused by diminishing testosterone levels in aging men. Unlike women, men do not have a clear-cut signpost such as the cessation of menstruation to mark this transition. Both, however, are distinguished by a drop in hormone levels. The bodily changes occur very gradually in men and may be accompanied by changes in attitudes and moods, fatigue, a loss of energy, sex drive and physical agility. Unlike menopause, which generally occurs in women during their mid-forties to mid-fifties, men’s “transition” may be much more gradual and expand over many decades. What’s more, studies show that this decline in testosterone can actually put one at risk for other health problems like heart disease and weak bones.
The finding that levels of testosterone in men decreased with aging raised the question of whether they too might benefit from sex hormone treatment. There is scant evidence that testosterone supplementation has any positive impact in healthy older men. The NIA is investigating the role of testosterone supplementation in delaying or preventing frailty. Preliminary results have been inconclusive, and it remains unclear if supplementation of this hormone can sharpen memory or help men maintain stout muscles, sturdy bones, and robust sexual activity. A small percentage of men with profound deficiencies may be helped by prescription testosterone supplements. Investigators are also looking at its side effects, which may include an increased risk of certain cancers, particularly prostate cancer. In fact, some studies suggest supplementation might trigger excessive red blood cell production in some men. This side effect can increase a man’s risk of stroke.
As research continues, the pros and cons of hormone replacement become more precisely defined. Sex hormone supplements appear to increase risk and provide few clear-cut benefits for healthy individuals.
Men may be helped by prescription testosterone supplements. These supplements often are prescribed to men whose bodies do not make enough of the hormone — for example, men whose pituitary glands have been destroyed by infections or tumors, or whose testes have been damaged. For these few men who have extreme testosterone deficiencies, supplements in the form of patches, injections, or topical gel may offer substantial benefit. Supplements may help a man with low testosterone levels maintain strong muscles and bones, and increase sex drive. However, what effects testosterone replacement may have in healthy older men without these extreme deficiencies will require more scrutiny.
In many instances, testosterone replacement in men with andropause can be highly effective and beneficial. It’s not for every man, of course. In various clinical studies, very good responses to testosterone have been reported for men with low-testosterone and they include:
- Improvement in mood and sense of well-being
- Increased mental and physical energy
- Decreased anger, irritability, sadness, tiredness, nervousness
- Improved quality of sleep
- Improved libido and sexual performance
- An increase in lean body mass, a decline in fat mass
- An increase in muscle strength (hand grip, upper and lower extremities)
- Potentially, a decrease in the risk of heart disease
Available as a synthetic hormone, testosterone is approved by the FDA for the treatment of low levels of testosterone (hypogonadism). The drug is given as an injection, a patch, a gel or an adhesive material applied directly to the gums.
According to the NIH, “. . . although some older men who have tried these treatments report feeling ‘more energetic’ or ‘younger,’ testosterone therapy remains a scientifically unproven method for preventing or relieving any physical or psychological changes that men with normal testosterone levels may experience as they get older.”
