Because steroid hormones play such a vital role in maintenance of health, knowledge of an imbalance in any one or more hormones can help illuminate the cause of health problems and provide a rational basis for correcting the imbalance through diet, exercise, or hormone supplementation. When the various glands manufacture the steroids they are released into the bloodstream bound to carrier proteins. This free or unbound hormone is what we want to measure, since it is active or bioavailable to the target tissues such as the breast, uterus, brain, and skin. The amount of steroid hormone that enters the salivary ducts and then saliva, is representative of the fraction of steroids in the bloodstream that are bioavailable to other tissues in the body.
Saliva collection is easy, can be done anywhere, any time and at a much lower cost.
Serum hormone testing is stressful, and the stress of a blood draw can sometimes alter the result. There is also an extra cost involved in drawing blood, independent of the cost for the test itself. Hormones in saliva are exceptionally stable, allowing wide latitude in collection and shipment. Samples can be stored at room temperature for at least a week without loss of activity, so samples can be shipped to the testing facility by regular mail. Blood, on the other hand, must be kept cool on ice packs, increasing costs for shipping as well as the likelihood of error due to improper handling.