Did You Get Your Free Testosterone Checked?

A frustrating situation that’s all too common:

You’re chronically tired. You’re sex drive is down. You’re failing to see any results from exercise, and the motivation to keep in shape is waning. You know that you’re experiencing the common symptoms of low testosterone, but the lab tests conducted at your annual physical show a healthy total testosterone level.

Diagnosing and confirming low testosterone is a complicated process that involves more than a single number on a lab report. It often requires specific lab testing and an expert interpretation of those results. 

Frankly speaking, many medical professionals don’t understand or appreciate the importance of measuring free testosterone levels.

A female researcher tests a patient's free testosterone.

What Is Free Testosterone?

Your body may be producing sufficient, healthy amounts of testosterone—revealed by a total testosterone reading—but it’s unable to use enough of the hormone produced to function at the level it should.


Sex hormone binding globulin (SHBG) and albumin, which are proteins produced by your liver, bind to your sex hormones and render them useless to your body. Only about 2% to 3% of testosterone remains available to be utilized by the body’s tissues. 

That small bit of usable testosterone is known as free testosterone.

If you have too much SHBG, what is considered a healthy total testosterone level for others could be insufficient for your body. You actually may have low testosterone because your free testosterone levels are too low. You will likely begin to experience the common symptoms of hypogonadism (the medical term for Low T), including:

  • Fatigue
  • Weight control problems
  • Low libido (sex drive)
  • Erectile difficulty
  • Concentration and memory deficits
  • Anxiety
  • Depressed mood
  • Weakened bone structure (osteoporosis)

Why Measuring Free Testosterone Matters

Free testosterone is more accurate when determining symptomatic low testosterone. The Endocrine Society guidelines recommend measuring free testosterone in men whose total testosterone concentrations are in the lower end of the normal range due to the frequency of misdiagnosis.

Ravi Jasuja, PhD, of Harvard Medical School, et al, published a review of male sex hormone testing protocols in Endocrine Reviews, and offers the following opinion: 

“If the free hormone hypothesis is correct, free testosterone should serve as the benchmark for biochemical confirmation of hypogonadism. Accurate determination of free testosterone values is therefore central to an accurate diagnosis of hypogonadism.”

Furthermore, not all free testosterone measurements are the same. In our opinion, the calculated free testosterone (cFT) is the best correlate for patient response. Analog tests like the “Testosterone, Free, Direct” assays often ordered have been rightly dubbed clinically useless. Academia promotes the use of equilibrium dialysis which is expensive, only done in a small number of laboratories, and can be significantly skewed by abnormal lipid shifts.

Too Little Free Testosterone—What’s Next?

You need to find out the truth about your condition, and that means a thorough lab test measuring your free testosterone.

You don’t have to live with your symptoms, because Low T is treatable.

The most effective way to restore and then maintain healthy testosterone levels for men who are chronically deficient (regardless of the root cause) is Testosterone Replacement Therapy (TRT).

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(Augie) Juan Augustine Galindo Jr. MPAS, PA-C

(Augie) Juan Augustine Galindo Jr. MPAS, PA-C started his career in healthcare as a fireman/paramedic in West Texas where he served on the Midland Fire Department from 1998-2004.   He became interested in testosterone treatment after seeing how hormone replacement doctors helped those suffering from low testosterone.   After graduating from the Texas Tech Health Sciences Center Physician Assistant Program, he moved to DFW where he currently lives with his wife and three children.

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