Why We No Longer Measure Total Testosterone
By William Lovett, M.D.
Many of our new patients come into our office with a Total Testosterone level as the only measurement of testosterone from their Family Physician or specialist. While we also used to measure this number, we have found that it isn’t the most accurate way to determine why you aren’t feeling as good as you used to. Why?
What is Total Testosterone?
Total Testosterone is the measurement of the total parts of testosterone in your body, including the inactive protein-bound component of testosterone. Testosterone only becomes active when it breaks away from a protein (commonly the sex hormone-binding Globulin). When this happens, it’s called Free Testosterone.
So, by definition, Total Testosterone does not tell us how much of the active Free Testosterone is floating around your body to bind to your receptors and make you feel good.
What Changed in Total Testosterone Measurement?
About a year ago, LabCorp – our lab partner – followed the trend of other labs and altered their Total Testosterone Reference Range on the lab sheet. The change occurred across the board because of the publication of a testosterone study.
LabCorp, like many labs, decided that they would change the reference range for healthy males because they felt they should eliminate the obese “unhealthy” males that were artificially lowering the Total Testosterone Reference Range.
Why is this Change Concerning?
Logic follows that the Reference Range should be raised by eliminating the group that was keeping it artificially lower. What happened was the exact opposite. LabCorp, like other labs, moved the Total Testosterone Reference Range lower.
Concerned, we contacted LabCorp and talked to one of their pathologists. He was familiar with the study and agreed with our conclusion. Unfortunately, the administrators still lowered the range, and could not provide the study’s raw data because it was conducted at several facilities that will not release it for verification.
This concerns us, because we have research that has changed the public lab reporting and the reasoning behind it is unchallenged and unverified.
What Does this Mean for You?
Put simply, we no longer measure your Total Testosterone because:
- It does not help us manage your active form of testosterone
- We can’t verify the data for the change in Total Testosterone measurement
- It will save you money for more important and accurate blood tests