As a premed student, I volunteered at a health clinic. One day, a patient mentioned to my supervising doctor that his testosterone levels were low. He knew this from a saliva test that his naturopathic doctor had recommended.
After the patient’s visit, I mentioned to the doctor that I didn’t know saliva could be used to accurately measure testosterone. My supervisor waved her hands dismissively as if to say, “such testing is total nonsense.”
The appeal of laboratory analysis of saliva is that it purportedly can be used to detect levels of the hormone testosterone, without the need for a needle stick and blood draw. A small number of doctors order this and home-testing kits are also available. These tests are often marketed online as a way to determine whether one has a testosterone imbalance that may cause problems ranging from low sex drive to accelerated aging.
Many doctors and researchers agree that saliva levels of the hormone cortisol accurately reflect blood levels. But most practitioners do not order saliva testing for testosterone because few studies support its validity. In fact, I only found three reasonable studies on the topic at all—two that support saliva tests for testosterone and one that does not.
In 2007, a group of Argentinean researchers from the University of Buenos Aires studied 52 healthy men and 20 who had low testosterone blood levels. Their data suggested that salivary testosterone levels were similar to the levels of testosterone in the blood serum (considered the “gold standard” for measuring testosterone).
A larger study from Saint Louis University, which looked at both serum and salivary testosterone levels in 127 healthy men, also found a strong correlation between salivary testosterone and all forms of serum testosterone.
On the not-so-positive side, researchers from Case Western University measured both salivary and serum testosterone on fifty-six postmenopausal women who were receiving testosterone or placebo patch for the treatment of hypoactive sexual desire disorder. They found little relationship between levels of salivary testosterone and serum testosterone.
There’s insufficient evidence at this point to support salivary testing as a reliable form of testosterone testing. Also, keep in mind that many health insurance companies do not cover salivary testing for testosterone (the cost is around $30). If your health care provider recommends a salivary test for testosterone or tells you that you have abnormal levels of testosterone based solely on a salivary test, request a blood test to confirm the findings.