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What you may not know about testosterone

March 20, 2023 | UCI Health
Man stays fit with a morning bike ride.

Therapy for low testosterone can alleviate symptoms and improve overall health, says Dr. Faysal Yafi, director of Men’s Health Services for UCI Health.

Think you know all about testosterone, the hormone that helps boys develop into men? Guess again.

Known as the "male” hormone — although women’s ovaries also produce it in small amounts — testosterone is responsible for more than just strength and virility in men, says urologist Dr. Faysal Yafi, director of Men’s Health Services for the UCI Health Center for Urological Care.

He highlighted four important things to know about this often-misunderstood hormone in a recent interview with Men's Health magazine.

Testosterone is highest in the morning

Testosterone levels are at their highest after a night of rest, between 7 and 10 a.m., says Yafi, noting that they “follow the circadian — basically the sleep — rhythm.”

For men with low testosterone, he suggests that morning workouts may help further boost those levels for some men.

But all exercise is beneficial. A recent study also shows that strength training and other exercise in the late afternoon or early evening when the body’s metabolism rate is highest may enhance muscle performance.

More than one type of testosterone

There are actually three kinds of testosterone, says Yafi, an associate professor and chief of men’s health and reconstructive surgery for the UCI School of Medicine's Department of Urology.

Free testosterone helps the heart pump more efficiently, aids in muscle contraction and more.

A second type of testosterone binds to the blood protein albumin, which carries hormones throughout the body.

Together, albumin-bound and free testosterone are known as bioavailable testosterone because they’re readily available for use throughout the body.

The third type, the sex-hormone binding globulin (SHBG), is not readily available for the body to use. But as men get older, Yafi says levels of SHBG and SHBG-attached testosterone increase.

Effects on brain and mood

Testosterone levels affect more than muscle growth and virility.

“There’s a lot of literature suggesting an association between low testosterone and depression and other mood disorders,” Yafi says.

Scientists are studying whether there may be an association between low testosterone and early onset memory loss, dementia and “foggy brain,” which Yafi describes as difficulty concentrating and getting motivated.

It's different from steroids

Testosterone replacement means increasing testosterone from low to normal levels, as you would for people who have low thyroid hormone, or diabetics who have low insulin,” says Yafi. “You are bringing them to normal levels.”

Anabolic steroids are synthetic versions of testosterone designed to bring total testosterone to excess.

They have been widely abused by some people to produce bigger muscles and better athletic performance.

Health effects of low testosterone

Low testosterone levels don’t just decrease one’s sex drive, Yafi says.

Other effects include:

  • Sleep and concentration problems
  • Fatigue
  • Decreased face and body hair
  • Loss of muscle mass and bone density
  • Mood changes

After blood tests confirm that low testosterone levels are at the root of any of these issues, a doctor may prescribe testosterone along with regular follow-up care.

Testosterone therapy doesn’t just alleviate symptoms but also improves overall health, Yafi says.

“Testosterone replacement therapy, when done in a clinically appropriate way, is extremely safe.”

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