Testosterone Levels Test: MedlinePlus Medical Test

Testosterone Test: Free & SHBG, High vs Low vs. Normal Levels

Testosterone supports muscle mass, libido, energy levels, mood, focus, sleep quality, bone density, metabolic health, and more, says Houman. So, having lower-than-optimal testosterone levels can lead to a range of physical, mental, and emotional side effects, he says. Research suggests that low testosterone levels may be more common among young men today compared to previous decades. Multiple large-scale studies have shown that average testosterone levels in men, including adolescents and young adults, have been on the decline over the past few decades, according to Houman.

Testosterone is a vital hormone that plays a crucial role in various aspects of male health, including muscle strength, sex drive, mood, and overall well-being. If you suspect that you may have low testosterone levels, it is essential to determine your actual hormone levels accurately. While there are several methods available to measure testosterone levels, some are more accurate than others. When it comes to understanding the levels of testosterone in the body, a testosterone levels test can provide valuable information. Testosterone is a hormone that is primarily produced in the testicles for men and in the ovaries for women.

Sometimes, the test needs to be retaken to confirm the measurements. Only a testosterone test can measure how much of the hormone is in your body and determine whether your level is within a healthy range. Your doctor uses it to diagnose conditions caused by too much or too little testosterone. In 2025, clinics like AlphaMan, a men’s health center specializing in hormone optimization, are rethinking how testosterone therapy fits into modern masculinity. Because when it comes to low testosterone, the stakes extend far beyond the gym. Even high-performing men balancing careers, families, and fitness can find themselves battling unexplained fatigue, diminished focus, low libido, and persistent sluggishness despite adequate rest.

While sedentary behavior, poor diet, and exposure to environmental toxins all decrease T levels over time, prevention is possible. Today, an estimated 25 percent of men over the age of 30 have low testosterone (or, less than 300 ng/dL of testosterone in their magnesium red blood cell test). However, data suggests that low testosterone impacts up to 40 percent of men over the age of 40. So, why is this widespread drop-off in T levels happening, exactly?

Low testosterone levels, also known as hypogonadism, can have a significant impact on a man’s overall well-being and quality of life. It is important to recognize the signs and symptoms of low testosterone so that appropriate treatment can be sought. While older at-home tests measured only total testosterone, newer-generation blood and saliva tests can also measure free and bioavailable testosterone. A blood test is a common way to measure testosterone (free and total), though saliva and urine tests are also available.

“Both can interfere with testosterone production, especially when used regularly or excessively during your teens and 20s,” he says. Research from the American Urological Association Education and Research Inc. suggests a link between marijuana use and lower testosterone levels. Meanwhile, one Journal of Clinical Medicine study reports that regular alcohol consumption can damage the Leydig cells responsible for testosterone production. To support hormone balance, Houman recommends cutting back on these substances or discussing a reduction plan with your healthcare provider.

Testosterone test results are described on a reference range of values, meaning a high and a low value between which testosterone levels are considered normal. Hyperandrogenism is more common in females and can manifest with virilization (the developmental secondary sexual characteristics more typical for males) and other symptoms. Males can also be affected, but symptoms are often non-specific or only appear when testosterone levels are excessively high. A testosterone test measures the amount of testosterone in the blood.

For males who have gone through puberty, the test is mostly used for symptoms of low T levels (testosterone levels which are too low). But other health issues may also cause low T, such as thyroid problems, long-lasting illness, or problems with the testicles. Instead, the blood test looks for your total testosterone levels, which counts free T as well as that bound to the proteins sex hormone-binding globulin (SHBG) and albumin.