Is testosterone replacement therapy safe? Take a look at the latest evidence in the February 2014 Harvard Men's Health Watch

Millions of American men use a prescription testosterone gel, patch, or injection to boost levels of the manly hormone. The ongoing marketing blitz promises that treating "low T" this way can make men feel more alert, energetic, mentally sharp, and sexually functional. However, legitimate safety concerns linger, as explained in the February 2014 issue of the Harvard Men's Health Watch.

"Because of the marketing, men have been flooded with information about the potential benefit of fixing low testosterone, but not with the potential costs," says Dr. Carl Pallais, an endocrinologist and assistant professor of medicine at Harvard Medical School. "Men should be much more mindful of the possible long-term complications."

Some studies have found that men taking testosterone have more cardiovascular problems, like heart attacks, strokes, and deaths from heart disease. Some physicians also have a lingering concern that testosterone therapy could stimulate the growth of prostate cancer cells. Yet the evidence is mixed, with some studies showing a lower cardiac risk with testosterone therapy and no apparent effect on prostate cancer.

In such uncertain times, men should take a cautious approach, Dr. Pallais says.

"I can't tell you for certain that taking testosterone raises the risk of heart problems and prostate cancer, or that it doesn't," Dr. Pallais says. "We need a large study with multiple thousands of men followed for many years to figure it out."

Until then, here are some tips for taking a cautious approach to testosterone therapy:

• Consider other reasons for symptoms attributable to low testosterone, like fatigue, low sex drive, and others. The problem may really be lack of a balanced, nutritious diet, regular exercise, and good sleep; depression; or relationship issues.
• Get an accurate measure of testosterone. This hormone should be measured between 7 am and 10 am, when it's at its peak. Confirm a low reading with a second test on a different day. Consider getting a second opinion from an endocrinologist.
• Men at high risk should approach testosterone therapy with extra caution. This includes men at high risk for prostate cancer; those with severe urinary symptoms from prostate enlargement; heart attack survivors; and those diagnosed with heart disease or multiple risk factors for it.

Read the full-length article: "Is testosterone therapy safe? Take a breath before you take the plunge"