Are saliva or blood tests more accurate when determining hormone levels?
Although blood testing is currently the most popular, both tests are accurate and useful. Blood tests measure levels of protein-bound hormones (inactive) and saliva tests measure free hormone levels (active). Since the inactive protein-bound form is present in much higher levels it has historically been easier to measure. Only in the last several years has saliva testing become more common. Many studies have been published about the value of saliva testing methods and it has become a mainstay of hormone research.
