In the not too distant past, when physicians were considering prescribing hormone replacement therapy for their patients, very few of them would bother to measure the levels of the various hormones involved. This applied both to the initial decision to prescribe and to the ongoing monitoring of therapy. For the initial decision, prescribers generally went with their own experience and the symptoms of the patient. If a woman came in with hot flashes or some other physical symptom associated with menopause, they received some sort of estrogen (usually Premarin and a synthetic progestin if they still had a uterus). Premarin is a form of estrogen derived from the urine of pregnant mares. Obviously, there is no normal reference range for horse estrogen in humans, so levels were not measured. If the initial therapy proved less than effective and since there was no baseline to objectively determine which way to adjust, the usual reaction was to increase the dosage until the patient either stopped complaining or gave up on therapy. Thus, physicians were not in the habit of measuring hormone levels.

Then along came bio-identical hormone replacement therapy, or BHRT. Since BHRT uses the same molecules our bodies produce, it became feasible to monitor levels. We could know that a woman in peri-menopause was making enough estrogen, but was deficient in progesterone or maybe testosterone. Or perhaps she was already low in all hormones. Without objective testing, it was just an assumption.

So what is the best way to monitor hormone levels? This is still a point of controversy. Blood testing is certainly usable to determine where the patient is in the “spectrum” of menopause and determine the course of action. But if a patient is administering hormones through the skin as a cream or gel, the best information we have at this point is to monitor with a saliva test. Saliva testing measures the hormones at the capillary level, whereas blood testing is from the blood serum. Saliva testing in this case is more sensitive than serum testing because it measures free, unbound hormones that are in their “active” state.

Another reason to monitor hormone levels is to determine the levels of the less well-known hormones, such as DHEA or testosterone in women. If this deficiency is documented by testing, there is more acceptance of DHEA and/or testosterone replacement by the prescribers, leading to a more thorough hormone replacement regimen.

Regardless of the method of testing, the monitoring of therapy is becoming more common, which is leading to more effective therapy and often results in using lower doses of hormone, which is safer for the patient.