Will Testosterone Therapy Keep Men
Young?
For: Better Sex in a Bottle? September 2002
For many years women have routinely taken estrogen in birth
control pills and have used pills and patches to replace their diminished
hormones after menopause or surgical removal of the ovaries. Testosterone
is, generally speaking, the male equivalent of estrogen—a master
hormone that controls many aspects of sexuality as well as secondary sexual
characteristics, such as facial hair, musculature, and voice quality.
Women also produce testosterone, though in much smaller amounts than men.
And men also produce estrogen.
Men don't experience menopause in the same sense that
women do—a marked cessation of fertility and a sharp drop in hormone
levels at midlife—but they do experience a gradual decline in testosterone
levels as they age, which is called andropause. (Actually, scientists
don't know if age-related declines in testosterone are universal,
since nearly all the data are from studies of Caucasian men of Western
European decent.) In some men, low levels of testosterone may depress
sexual desire, as well as lead to loss of muscle strength and mass, an
increase in fat tissue, a decrease in sexual activity, depression, and
other adverse effects. It is, of course, hard to blame all this on decreased
testosterone alone, as many other factors can produce the same effects
in older men. In fact, it's uncertain exactly what role declining
levels of testosterone (and other hormones) play in the aging process.
Still, some people think that aging men should be getting
hormone therapy just like women. If you've read the recent batch
of articles in major magazines, you may have concluded that you can be
sexier, manlier, a better athlete, and so on if you take testosterone,
and that the risks are negligible. Some people put a sort of sexism-in-reverse
spin on it: why are men being neglected?
Before you seek out therapy, consider this:
• Hormone replacement therapy (HRT) for women has been extensively studied. The early high-dose regimen of estrogen turned out to be risky, and in spite of all that's been learned since, there's still uncertainty about the benefits and risks of HRT. Much less is known about testosterone therapy.
• Testosterone declines in men as they age, as we've said. Though physicians have defined a range of what's "normal" at various ages, levels vary greatly from man to man, and even during the course of the day in the same man. No one knows what the optimal levels are.
• Many older men remain fit, stay sexually active, and sometimes father children, even with a decline in testosterone.
• Supplemental testosterone has potential side effects, including an increased risk of prostate cancer, an adverse effect on blood cholesterol levels, and interference with the normal functioning of insulin. Liver damage, dry skin, sleep apnea, breast growth, fluid retention, an increase in red blood cells, and outbreaks of acne are other possible risks. Some people worry that excess testosterone contributes to violent behavior. In fact, there is virtually no scientific evidence for this.
• Testosterone is usually hard to take. Injections cause a rapid rise in blood levels, followed by a rapid drop. Skin patches can be uncomfortable, have to be replaced daily, and may cause irritation.
Testosterone pills are ineffective; modified-testosterone
pills are effective, but toxic to the liver. A new treatment called AndroGel,
just approved by the FDA, is rubbed on the arms, shoulders, and/or abdomen
once a day. All these treatments are expensive: AndroGel costs almost
$2,000 a year.
There's a place for male HRT, but not often
Testosterone deficiency is a medical condition that can
be diagnosed and treated only by a doctor. Some genetic disorders and
a variety of other conditions (such as HIV infection and liver disease),
plus certain medications, may result in a dramatic drop in blood levels
of testosterone—this can happen in young as well as older men. It's
estimated that anywhere from 5% to 35% of men over 60 have low levels,
depending on how these are defined.
In general, it's hard to diagnose deficiency—it
is seldom clear-cut, since there are few symptoms specific to testosterone
deficiency.
Some men will benefit from hormone therapy, but this is a serious decision,
and the long-term risks are unknown. Men with liver, heart, or kidney
disease, cancer, diabetes, enlarged prostate, or certain blood disorders
should not take testosterone.
Women, too, are sometimes treated with testosterone to counteract
the decline in sexual interest that may follow surgical removal of the
ovaries or natural menopause.
Though testosterone is essential for making men masculine, lower levels as you grow older do not mean you are less of a man. An older man in good health can do everything a younger man can do—continue to do productive work, enjoy leisure-time activities and exercise, have an active sex life, and so on. Hormone levels are only one part of the equation.
And by the way: Testosterone
is available only by prescription. However, numerous websites and health-food
stores sell testosterone-like substances such as androstenedione and other
"prohormones" that are supposed to be "all natural"
ways to boost testosterone. These are aimed especially at young athletes,
but also at men who want to lose weight, sleep better, gain energy, and
of course feel sexier. Such "dietary supplements" are completely
unregulated. If they do act like testosterone, they probably carry all
its risks. No one should self-prescribe hormone therapy.
UC Berkeley Wellness Letter, October 2000
