Testosterone Lab Tests

Several lab tests can be used to measure testosterone levels in the body. Some of the most common tests include:

1. Total Testosterone: This test measures the total amount of testosterone in the blood, free (unbound) and bound to proteins. It is considered the most accurate way to measure testosterone levels.

2. Free Testosterone: This test measures the amount of unbound, or "free," testosterone in the blood. It is considered less accurate than total testosterone, as it is affected by changes in protein levels in the blood.

3. Bioavailable Testosterone: This test measures the amount of testosterone available to the body's cells. It includes both free testosterone and that bound to a specific protein called sex hormone-binding globulin (SHBG).

4. LH and FSH: These are hormones produced by the pituitary gland which stimulate the testicles to produce testosterone; low testosterone levelscan cause an increase in these hormones, so measuring them can indicate the testicle's function in producing testosterone.

5. DHEA-S: This test measures the level of the hormone dehydroepiandrosterone sulfate (DHEA-S) in the blood. DHEA-S is a precursor to testosterone and other hormones, so changes in its levels can indicate changes in testosterone production.

It's worth noting that testosterone levels can vary throughout the day and can be affected by factors such as stress, illness, and recent exercise. Therefore, these tests are usually done in the morning, when testosterone levels are at their highest. Also, it's essential to consult with a healthcare professional to properly interpret the test results, as many factors, including age, medications, and medical conditions can influence the results.