Diagnostic testing has a long, bloody (i.e., blood-based) history, and when a physician orders a test, the usual response is to strap on a tourniquet, pull out a syringe, and extract a venous blood sample. For some tests, though, and, especially to measure levels of steroid hormones such as estrogen, testosterone, or cortisol, a blood sample might not be the best choice.
Consider putting away the syringe, relieving the patient of the fear and discomfort of a needle stick, and collecting saliva samples instead. Not only are today’s saliva tests highly sensitive and accurate, but saliva diagnostics also offer the most reliable method for measuring levels of free, bioavailable hormones.
Saliva testing has come a long way since it first made its appearance in the 1980s. Advances in sample collection methods and increasingly sensitive and robust assays, have led to substantial growth in the saliva diagnostics market. With more laboratories offering saliva-based testing for an expanding range of applications, the unique advantages of saliva diagnostics have gained widespread recognition.
Unlike blood-based tests, saliva diagnostics can measure the amount of free, unbound hormone that is available to act on a target tissue. About 95-99% of steroid hormones circulating in the bloodstream are bound to carrier proteins. Saliva contains unbound, bioavailable hormones. Therefore, salivary concentrations better represent circulating levels of free hormones, 1 which are likely to affect the body and be responsible for symptoms related to excessive or deficient hormone levels.
Among the advantages of saliva tests versus blood tests are the non-invasive and stress-free nature of saliva sampling. Hormone testing may often require baseline measurements as well as periodic tests to monitor a particular condition or adjust therapeutic dosing. Saliva sampling must be done correctly, but today’s collection devices make it easy, and patients can collect their own samples during the day or night as needed, to measure fluctuations in hormones such as cortisol or melatonin, for example. Saliva testing also provides an easy and convenient way to acquire the periodic measurements of various sex hormones in women of reproductive age for the treatment of fertility problems, or in peri- or post-menopausal women to adjust and personalize dosing in hormone replacement therapy.