Harvard Health Letter

Considering testosterone therapy?

35% of men over 45 may have low testosterone levels.

Testosterone therapy is more popular than ever, with global sales expected to reach $5 billion by 2017. The hormone offers the potential to reverse the clock by improving energy, mood, and sex drive, to name a few benefits. But the therapy may not be right for everyone, and may pose risks for some.

Low testosterone

After age 30, a man's testosterone level begins falling about 1% per year. The decline affects more than just sexual function. Testosterone (T), made in the testicles, is also necessary for bone health, mental clarity, muscle strength, and red blood cell production. Sometimes the body is unable to make enough T because of a problem with the testicles or the pituitary gland.

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