Why test saliva? 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.

Are the levels of steroid hormones in blood and saliva the same? When the various glands manufacture the steroids, they are released into the bloodstream and bound to carrier proteins. Only a small fraction (1-5%) of a given amount of steroid hormone breaks loose from the carrier protein in the bloodstream and is free to enter target tissues. 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.

Many studies in the scientific literature have shown that there is a strong correlation between the levels of steroid hormones in saliva and the bioavailable levels of steroids in the bloodstream. 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.

Further, the hormones are lipid soluble molecules. That means they dissolve in oil or fat - not in water. Blood cells are enclosed in a membrane that is high in fat so the hormones easily “hitch a ride” on blood cells. When you get a “blood test” the laboratory actually tests the serum, the water part of the blood. There is little if any hormone dissolved in this portion of the blood. Dr. John Lee said that by looking at blood (serum actually) you are looking in the wrong place! Blood and serum tests regularly give inaccurate readings.

A prominent scientist in Oregon did a study where he administered a dose of progesterone to a woman. It was applied to her skin. He then began an hourly test of both saliva and blood. After 4 hours, the saliva progesterone level had risen significantly. The blood test for progesterone was relatively flat - showing no significant change. After peaking, the saliva levels began to decline and some 8 hours later the levels were about where they were before the patient applied the progesterone cream. The blood test never changed during this time.

Advantages of saliva vs. blood testing of steroid hormones. 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. Blood has to be drawn at a doctor's office or drawing station, and it is more difficult to obtain samples at the desired times (e.g. early am), multiple times through the day or late evening. 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.

Finally, as outlined in the following section, saliva hormone testing allows you to take more control over your own health. Saliva testing may help you to gain insight into health problems before you see your doctor. It will also allow you to monitor an OTC hormone supplementation program (e.g. natural progesterone cream and DHEA are widely available) if improvement in quality of life, disease prevention, or anti-aging is your goal.