DR. PINKERTON: No, it isn’t. Although compounded bioidentical hormone therapy is often prescribed on the basis of salivary hormone testing, there is no scientific evidence that a correlation exists between a patient’s symptoms and salivary hormones, or that salivary hormone testing reflects what is happening at the tissue level. As Fugh-Berman and Bythrow have observed, this type of testing is often used to convince asymptomatic consumers to use hormones—or symptomatic women to take higher dosages. That practice is likely to lead to adverse events.5 The practice also directly contradicts evidence-based guidelines, which recommend that hormone therapy be individualized on the basis of symptoms, not hormone levels.6
There are no published studies in the peer-reviewed literature that show that salivary testing is a reliable measure on which to safely and effectively base dosing decisions. Indeed, The Endocrine Society issued a position statement that notes, among other issues, that salivary hormone tests are “inaccurate and should not be considered reliable measures of hormones in the body.”7 The American College of Obstetricians and Gynecologists also advises against salivary testing, observing that:
- 1) there is no biologically meaningful relationship between salivary sex steroidal hormone concentrations and free serum hormone concentrations
- 2) there is large within-patient variability in salivary hormone concentrations. Salivary hormone levels vary depending on diet, time of day of testing, the specific hormone being tested, and other variables.3
Do bioidenticals protect against cancer?
OBG MANAGEMENT: Some reports mention the fact that many women believe that bioidentical hormones—specifically, estriol—can reduce their risk of breast and endometrial cancer. Is there any truth behind this belief?
DR. PINKERTON: Estriol is a weak estrogen. There is no evidence that, if it is given at a dosage high enough to relieve symptoms, it is any safer than estradiol.
In regard to endometrial cancer, if the exogenous estrogen—bioidentical or otherwise—is unopposed or inadequately opposed, the risk of endometrial cancer is elevated. The problem is that it is hard to determine whether estrogen is being adequately opposed, particularly when transdermal compounded progesterone is given, because the progesterone molecule is too large to be well-absorbed systemically.9
In regard to breast cancer, estriol is a less potent estrogen than estradiol, but it is believed to carry the same risks if it is dosed at effective levels. There is nothing about estriol per se in the peer-reviewed literature that shows that it protects against breast cancer.
The data on risk of breast cancer with estrogen therapy is confusing, with potentially higher risks if estrogen is combined with progestogen. Most of the data we have on estriol come from animals, but a study from 1980 in humans showed that, when older women with breast cancer were treated with estriol, 25% had increased growth of metastases.8
How do you monitor use of bioidentical hormones?
OBG MANAGEMENT: When you do prescribe a compounded bioidentical hormone, how do you monitor the patient?
DR. PINKERTON: First, I want to reiterate that I prescribe these hormones after considerable patient education about FDA-approved options and their potential risks. Second, when a patient needs or requests hormone therapy, I recommend conventional therapy. Only when she cannot tolerate or refuses FDA-approved drugs do I consider prescribing compounded bioidentical hormones—which, as I said earlier, are assumed to carry risks identical to those of FDA-approved hormones.
In some cases, I provide gynecologic care for patients who obtain compounded bioidentical hormones from other sources. What I will sometimes do, just to give myself some idea of how much estrogen they are getting, is to measure the peak and trough estradiol and estrone levels. That is, I measure the hormone level within 4 hours of the patient taking the drug to see how high it goes, and again about 12 hours later to see how low it goes. I measure both because estradiol may be peripherally converted to estrone.
Regrettably, we don’t know what to do about the various hormone levels. It isn’t like treating thyroid disorders; we normally dose estrogen therapy based on symptoms.
Who pays?
OBG MANAGEMENT: Who pays for salivary testing and compounded bioidentical hormones? Does health insurance cover them?
DR. PINKERTON: Like other “natural” products, compounded bioidenticals may cost more than their commercially prepared counterparts and often are not covered by insurance. In addition, prescribers may charge more for a “consultation” than do practitioners who accept insurance; they also may recommend salivary testing, which is expensive. Patients can end up paying large sums out of pocket.
As Rosenthal noted, many women do not appear to be concerned about the added costs.2 That may be because compounded bioidentical hormone therapy is usually offered to economically advantaged patients.2