In his early 30s, David Becker started feeling lousy. He was constantly tired, his interest in sex took a plunge and he lacked the motivation to do anything outside of work. “Life just felt bleak,” he said.
Mr. Becker, a nurse in Tulsa, Okla., consulted a doctor who ran a variety of blood tests and suggested antidepressants. But Mr. Becker didn’t want drugs, so he did what many people who are unhappy with a diagnosis do: a Google search. He decided his symptoms indicated low testosterone, a condition tied to fatigue, flagging mood and a reduced sex drive.
His doctor had tested his testosterone, putting it at about 400 nanograms per deciliter (a unit used to measure tiny concentrations of liquid). It was within a typical male range, albeit on the lower end. Still, Mr. Becker began looking for ways to boost it. He started lifting weights, ate more healthy fats and made a point of sleeping eight to nine hours every night. “It kind of became an obsession,” he said.
Men have been drawn to virility enhancement for centuries, either to treat diseases or restore youthful vigor. Today, many have turned to increasing their testosterone levels (whether through lifestyle changes, supplements or pharmaceuticals) to give them confidence, fight aging, raise physical or mental performance and generally help them feel their best.
Typically this starts with testing, then often leads to testosterone replacement therapy through a doctor or specialized “low T” clinic. During the pandemic, however, more men struggling with feelings of malaise have turned to virtual options for testosterone testing and treatment, spurring interest in what was already a $1.7 billion industry.
Everlywell, an at-home testing company, saw sales for its testosterone test triple last year. And Hone Health, a membership-based online hormone optimization clinic that sends blood tests to men and monthly treatments to those with low testosterone, has amassed more than 7,000 members since 2020, according to Saad Alam, the company’s founder and chief executive.
“It’s really never been easier to pursue some of these diagnostic tests and treatments,” said Dr. Joshua Halpern, an assistant professor of urology at Northwestern University’s Feinberg School of Medicine who has written about the trend. But, he added, while online services can increase access to quality care, they also have the potential to harm.
Raising testosterone levels can be beneficial for some, but the hormone is just one of many factors that might explain symptoms such as low mood, reduced sex drive and a lack of energy. So just how important are testosterone levels, and when should men worry about them?
What is low testosterone?
Testosterone plays an important role in overall health, regardless of a person’s sex. The hormone is sometimes prescribed off label to treat low sex drive in post-menopausal women and is a key part of gender-affirming care for transgender and nonbinary people. Advertising around the benefits of optimizing testosterone, however, typically targets those assigned the male sex at birth.
In males, testosterone is mainly produced in the testes, and regulated by the brain’s hypothalamus and pituitary gland. Men with blood tests consistently showing low testosterone levels, along with signs or symptoms such as a depressed mood, lack of energy, low bone density, erectile dysfunction or decreased sex drive meet the criteria for an endocrine condition called hypogonadism.
Different countries and professional organizations have slightly different cutoff points in diagnosing the condition, but generally a concentration below 250 or 300 nanograms per deciliter of blood is considered low, said Dr. Shalender Bhasin, an endocrinologist and professor of medicine at Harvard Medical School.
The difference between healthy and unhealthy levels is rarely clear cut, however. Men with testosterone levels above 300 can still have a deficiency, and a low testosterone level may not produce symptoms. “It’s all a continuum,” said Elizabeth Platz, professor of epidemiology at Johns Hopkins University’s Bloomberg School of Public Health, who has studied testosterone. Researchers have defined a typical healthy range, but they have yet to determine a specific number within it that is optimal for any given man, she said.
Hypogonadism also has several underlying causes, but experts disagree about whether all should be treated with testosterone. The U.S. Food and Drug Administration has approved testosterone products for hypogonadism caused by conditions that affect the testes, pituitary gland or hypothalamus, which affects less than one percent of men, said Dr. Bradley Anawalt, a reproductive endocrinologist at the University of Washington School of Medicine. But many men have low testosterone for others reasons: a high body mass index; a sedentary lifestyle; certain drugs; and conditions such as sleep apnea, diabetes and anemia. Levels also tend to decline as men age, with roughly 10 percent of men in their sixties classified as hypogonadal.
As testosterone declines, some men may experience a low libido, depressed mood or decreased energy even if their levels are not technically low, Dr. Anawalt said, adding that some doctors will not prescribe testosterone to these men, but others might.
A drop in testosterone from the high end of normal to the lower end doesn’t always indicate a problem, though. Testosterone levels fluctuate from day to day, and even within a single day. Some tests are also notoriously inaccurate, Dr. Anawalt said.
What are the benefits of increasing testosterone?
For hypogonadal men, normalizing testosterone levels has clear benefits: increased sex drive, greater bone density, leaner body mass and more muscle strength. Testosterone has also been linked to small improvements in mood.
Some hypogonadal men report that taking testosterone increases their energy and ability to concentrate, but the effect may be small and results have been mixed. A set of clinical trials in 2018 found that testosterone treatment did not improve cognition or fatigue in older men with low levels of the hormone.
For men whose levels already fall within the normal range, the evidence-backed benefits of increasing testosterone are limited, Dr. Bhasin said. Raising levels within the typical range can increase muscle size and strength, which is the reason some bodybuilders take heavy doses. But even gaining muscle is not a given.
Still, some find it tempting to try. Scot Singpiel, a 51-year-old podcast manager in Salt Lake City, has long struggled to build muscle, which made him self-conscious.
“I was a skinny ranch kid in a world where other ranch kids were big and beefy and strong,” he said. His testosterone levels were roughly 600 nanograms per deciliter, the middle of the typical range, but in 2012 he tried a testosterone cream prescribed by a naturopathic doctor. A year and a half into treatment, however, he hadn’t noticed any positive changes and was forced to take pills to correct a hormone imbalance caused by the testosterone. Eventually he stopped using the cream.
“It just got to the point where it was more hassle and I really wasn’t getting a benefit,” he said.
What are the downsides of testing for and trying to raise testosterone levels?
For some, however, the side effects of testosterone therapy are more serious. Over time, it can suppress a man’s natural ability to produce the hormone and lead to infertility. In 2015, the U.S. Food and Drug Administration put out a warning that testosterone might increase the risk of cardiovascular events, and in the past decade, thousands of men have filed lawsuits against the makers of testosterone products, claiming that the drugs cause heart attacks, strokes and blood clots.
Long-term studies on testosterone therapy’s safety are lacking, however. “In the absence of clear evidence that it’s safe, we wouldn’t want to just prescribe it willy-nilly,” Dr. Anawalt said.
There are several other problematic aspects of testosterone optimization, starting with testing. Labs use different techniques for measuring the hormone, and their results can vary widely. As of 2021, the Centers for Disease Control and Prevention had certified roughly 20 tests, but unstandardized, inaccurate tests are still widely available, which may lead to inappropriate decisions, according to Dr. Anawalt. Many at-home tests measure testosterone in saliva, for example, which does not translate directly to results measured in blood, he said.
Men should use certified tests, he said, and should only get one if they have symptoms such as osteoporosis, low libido or erectile dysfunction. Low libido, fatigue and depressed mood can be indicative of many conditions, including some mental health issues, Dr. Bhasin said. Focusing on testosterone to improve these symptoms may mean the real issue goes untreated. Testosterone treatment can also cost up to thousands of dollars per year.
Men who are concerned about their testosterone should seek guidance from a urologist, endocrinologist or primary care provider familiar with hypogonadism, Dr. Halpern said. Supplements marketed as “testosterone boosters” aren’t regulated, and may come with risks. Exercising regularly and losing weight, however, might increase testosterone levels or slow age-related declines as well as improve low energy, depressed mood and reduced libido independently of testosterone.
Mr. Becker, for instance, felt better and saw his testosterone level nearly double within six months of adjusting his lifestyle with more exercise, plenty of sleep and a better diet.
Although testosterone is not always the solution to health woes, it offers an appealing magic bullet, Mr. Singpiel said. He plans to get his levels checked again soon, but he suspects that the way forward is simply to lead a healthier lifestyle. “Sometimes it’s just the basic stuff,” he said.
Chloe Williams is a science journalist who covers health and the environment.