Can hormone therapy really keep you young?

Hormone therapy to slow the aging clock sounds enticing. But like anti-aging supplements and many prescription drugs touted to halt age-related decline, taking hormones in the hope of staying youthful longer can not only be ineffective, but it can also be hazardous to your health.

Testosterone replacement

Ads trumpet the lethargy and lost libido that can accompany low testosterone levels in men. A daily dose of the hormone, the ads suggest, will take care of "low T," boosting your sex drive and helping you reclaim your more energetic self.

Reality check. Testosterone treatments are Food and Drug Administration-approved only for men with diagnosed hypogonadism, a failure to produce enough testosterone because of disorders of the testicles, pituitary gland, or brain. The American Association of Clinical Endo­crinologists and the Endocrine Society advise against prescribing them without a confirmed deficiency.

That's because the therapy has risks. The FDA recently required prescription testosterone (including AndroGel, Aveed, Axiron, Fortesta, and Testim) to carry a warn­ing about the possible higher risk of heart attack and stroke.

In June 2014 the agency began to require a warning about blood-clot risks. Other research suggests that the treatment might encourage the growth of existing prostate cancer, boost the risk of sleep apnea, and cause an enlarged prostate, enlarged or painful breasts, swollen feet, and a lower sperm count.

If you're experiencing low energy or libido, see a doctor. Stress, medications, diabetes, obesity, or too little sleep or exercise might be at fault.

Learn why you should also skip "anti-aging" pills, and see our Choosing Wisely campaign to find out more about how to avoid unnecessary medical care.

Human growth hormones

HGH fuels growth in children and adolescents, and helps maintain tissue and organs. Some say that injections of it can increase muscle mass, reduce body fat, aid skin elasticity, and slow bone loss.

Reality check. The FDA has approved HGH only for three adult conditions, including growth-hormone deficiency caused by pituitary damage. For anyone else, taking it is a risky proposition. It's illegal for doctors to write prescriptions for—and distribute—HGH for anti-aging. Any benefits may be modest and tem­porary. HGH can cause carpal tunnel syndrome, swelling, joint pain, organ enlargement, and type 2 diabetes. It may also increase cancer risk.

"Stay away from any product that claims it will make you live longer, especially if it's combined with growth hormone," says S. Jay Olshansky, Ph.D., a professor of public health at the University of Illinois in Chicago. "Growth hormone may make you live ‘shorter.' "

Bioidentical hormones

Prescription hormone therapy (HT) is generally considered to be a reasonable short-term solution for hot flashes and other menopause symptoms. But some people recommend long-term use of compounded bioidentical hormones to help women look and feel younger, says Margery Gass, M.D., executive director of the North American Menopause Society. (She says that bioidentical hormones are chemically the same as hormones that your body produces. Compounded drugs are mixed in certain pharmacies.)

And some claim that compounded bioidenticals are superior to traditional HT because they're customized.

Reality check. Compounded bioiden­tical hormones aren't approved by the FDA (though some traditional HTs have FDA-approved bioidentical hormones), so there's no guarantee that they contain safe levels of hormones. Compounded bioidenticals carry the same risks as traditional HT—an increased likelihood of blood clots, breast cancer, heart disease, and stroke. And those risks grow with long-term use. Estriol, a type of estrogen, is found in some compounded formulations, but its safety and effectiveness aren't known.

So avoid compounded bioidenticals. If you think that you need HT to ease menopause symptoms, discuss the risks and benefits with a doctor, Gass says.