Do saliva tests give the same results as blood tests?
Blood tests measure the hormone that is protein bound but water soluble, whereas saliva testing measures the hormone that is in a fat-soluble form. However, saliva tests and blood tests will provide the same information so long as the person interpreting the results realises these differences and does not expect the levels to be the same for blood as for saliva. What ever results are obtained these must be compared with the normal levels for that method of measurement. What is the difference between protein bound water soluble hormones and fat soluble hormone? The difference lies in the different levels of activity of the hormone. For a hormone to be biologically active it needs to be fat-soluble so that it can pass into the tissues. The hormone in the protein bound water-soluble form, which is transported in solution in the serum, is the form in which it is produced by the endocrine gland. In its protein bound state only about 9% of the hormone is biologically active. Fat-soluble horm
