Testosterone Levels

Is There a Simple Blood Test for Low T?

In Testosterone by Optimal Health MD

Hypogonadism or Low Testosterone is a condition that affects the aging male population. It is a medical term that describes the decreased function of the male testicular glands, causing little or no production of testosterone hormones.  There are many signs and symptoms that male patients experience when afflicted with Low T

  • Decrease in Sex Drive and Intimacy
  • Irritability or Quick Bursts of Anger
  • Extreme Fatigue Bordering on Exhaustion
  • Difficulty Sleeping or Outright Insomnia
  • Increased Body Fat & Excessive Weight
  • Loss of Lean Muscle Mass and Strength
  • Loss of Bone Density – Osteoporosis

The Low T Test

A simple blood test panel is used by your Testosterone Therapy Doctor to check the testosterone hormone levels in your body.  When the levels are low, your hormone treatment doctor will prescribe a customized treatment plan to normalize your testosterone levels and get you back to optimum condition.

Testosterone Therapy will boost your low testosterone levels back up into the normal range. An increase in your Free Testosterone or Bio-Available Testosterone will help restore your vitality, stamina, and sexual desire. 

Many men who take testosterone, especially injections, experience a boost in their sex drive and frequency of sex, the ability to build muscle and increase muscle strength, the ability to burn fat and lose weight, an improved sense of well-being, a good mood, and renewed enthusiasm for daily living and their relationships.

Testosterone Test Preparation


No preparation is required before the test.  Often, our Testosterone Treatment Doctors want the test to be done in the morning, when testosterone levels are highest. Although fasting is ideal for eight to 12 hours before a testosterone hormone test, there is no absolute requirement for 12-hour fasting prior to the test. Our doctors will have your lab test results in one to two days. The blood test will check your Free Testosterone and Total Testosterone Levels. Keep in mind that testing only Total Testosterone levels is not as good an indicator for hormone deficiency as measuring your Free or Bio-available levels.

Testosterone Testing is used to Diagnose Hormone Health Conditions in Men – Andropause, Hypogonadism, Erectile Dysfunction (Impotence)

Low T levels can be caused by pituitary or testicular functional problems, prescription drugs or medications, aging, andropause (male menopause), obesity, injury, and can cause ED or Erectile Dysfunction due to androgen deficiency. Endocrine doctors, urology doctors, age management and anti-aging medicine professionals will prescribe TRT or Testosterone Replacement Therapy to replace lost or low male sex hormone levels.

The lab tests used for diagnosing Low T levels will provide blood serum results for the amount of androgen found in Total Serum Testosterone; Free Testosterone; Bioavailable Testosterone (Free androgens plus those loosely bound to blood plasma albumin); and levels of SHBG (Sex Hormone Binding Globulin). There are basic hormone test panels and comprehensive hormone test panels that better help your treating doctor get a more detailed result of your endocrine profile. Other tests include LH (Luteinizing Hormone) levels, FSH levels (Follicle-stimulating Hormone), Estradiol (estrogens), thyroid, red blood cell count, and DHEA levels. 

TTST – TTBS – TTFB – Lab Test Results

Types of Androgen Hormone Testing. There are three main types of testosterone tests – from a basic test to a more comprehensive measurement of all types of testosterone circulating in the blood: 

  • TTST – Testosterone, Total, Serum
  • TTBS – Testosterone, Total and Bioavailable, Serum
  • TTFB – Testosterone, Total, Bioavailable, and Free, Serum

Normal Testosterone Levels. Laboratories have reference ranges for what they consider normal testosterone hormone levels. In fact, what is considered a normal androgen level can vary from lab to lab and the expertise of your endocrine doctor becomes invaluable in determining if the results of your blood test place you into a deficiency or borderline deficiency. The variations in lab test reference ranges for total androgen blood serum levels are apparent with many labs using 240-950 ng/dL in their lab test reports, and others with test result ranges from 300 to 1,000 or even 1,200 ng/dL. The main thing to keep in mind with regards to Low T testing is that many men who have a near normal Total Serum Testosterone reference level can still exhibit symptoms of low testosterone because their Free Testosterone levels are low.

Free and Bio-Available Androgen Levels. The typical range for free blood serum testosterone is 9-30 ng/dL and bio-available blood serum 80 to 200 ng/dL. The androgens Free Testosterone and DHT (dihydrotestosterone) circulate in the blood plasma unbound or freely at about 2 percent to 4 percent. The bound androgens consist of specific protein bound (60 percent) and non-specific protein bound (36 percent) which accounts for the remaining 97 percent to 98 percent.

How are these remaining androgens bound? The remaining testosterone is bound to specific plasma proteins called SBHG or Sex Hormone-Binding Globulin and to nonspecific plasma proteins known as the albumin. The SHBG-bound androgens are biologically unavailable for use by a man’s body whereas those non-specific loosely bound to albumin are relatively bio-available. For male hormone replacement and testosterone optimization purposes, Free testosterone, which is entirely unbound, and Bioavailable testosterone, which is weakly bound, are the most important measurements to consider.