Published May 18 2015
Most “hormone doctors” utilize blood testing when testing the sex hormones such as estrogen, progesterone, and testosterone. Although this type of testing can be beneficial in postmenopausal women, it has limitations in those who are cycling or in perimenopause. The goal of this article is to discuss five different methods of testing the sex hormones, and so after reading this I’m hoping you’ll have a better understanding with regards to what type of test will be the best option if you choose to get the sex hormones tested.
Before discussing the five different methods I want to briefly differentiate between “free” hormones and “bound” hormones. Most hormones in the blood are bound to transport proteins. An example of a transport protein is albumin, which binds to some of the hormones, such as progesterone. However, progesterone also binds to another hormone called transcortin. A small amount of estrogen and testosterone bind to transcortin, but these hormones are mostly bound to a transport protein called sex hormone-binding globulin (SHBG).
Free hormones aren’t bound by a protein, and are therefore considered to be active. So for example, even though we’re talking about the sex hormones, I’d like to use the thyroid hormones as an example which hopefully will make this easier to understand. A thyroid panel might test for total T3 and free T3. Total T3 will mostly be bound to the transport protein called thyroxine-binding globulin (TBG), whereas free T3 won’t be bound to a transport protein, and therefore free T3 can bind to the thyroid receptors. When conducting a thyroid hormone panel it can be useful to look at the total T3 and total T4, but every endocrinologist should also test the free T3 and free T4 levels. Unfortunately not all endocrinologists test the free thyroid hormones, as many will only test for the TSH and T4, while others will rely on the TSH alone.
The same concept applies to the sex hormones, as while testing for the bound form of the hormone does have some value, it is also beneficial to look at the free hormones. Once again, most blood tests are measuring mostly the bound form of the hormone, whereas saliva testing is only looking at the free form of the hormone. This is why someone might obtain a blood and saliva test for a specific hormone and the tests will have different values. In other words, progesterone might be normal in the blood, but the free form tested through the saliva can show up as being depressed.
What I’d like to do now is discuss five different methods of testing the sex hormones:
- Serum testing. Serum (blood) testing is what is commonly utilized by most medical doctors. This almost always involve a one sample test, and unless otherwise indicated it usually tests mostly for the bound form of the hormone. So for example, when a doctor orders a blood test for estradiol or progesterone, this is bound to a transport protein. Serum testing can be valuable when looking to evaluate a single sample, although it has limitations when trying to evaluate the hormones in cycling women, and to a lesser extent those in perimenopause. With regards to cycling women, remember that the hormones will fluctuate, and so not surprisingly a cycling hormone panel which involves collecting a sample every few days of one’s cycle will provide more information than a single sample.
- One sample saliva test. Saliva testing is rarely used by medical doctors. The benefits of saliva testing is that it evaluates the free form of the hormone. When attending the hormone module for the Institute of Functional Medicine, most of the medical doctors who taught at the conference utilized saliva testing for the adrenals, but not for the sex hormones. Although I do utilize one sample saliva testing to look at the sex hormones in patients who are postmenopausal, a few studies have questioned the accuracy of saliva testing to measure testosterone levels (1) (2). The good news is that the free testosterone can be tested through the blood.
- One saliva sample tested two weeks apart. In perimenopausal women a one sample saliva test taken approximately two weeks apart can be beneficial. The main reason for this is to see the fluctuations in the hormones. So for example, if a woman has an irregular menstrual cycle and is only cycling every few months, she might not be a good candidate for a cycling hormone panel, and a perimenopausal hormone test might be a better option in this case. Or if a woman hasn’t had a cycle in six to twelve months and wants to see if there are fluctuations in the hormones then this test would be a good option.
- Cycling hormone panel. With regards to cycling women, most medical doctors will perform a one sample blood test during the second half of the cycle, also known as the luteal phase. Of course the problem with this type of testing is that with a cycling woman, the hormone levels will greatly fluctuate throughout her cycle. And so just because someone has a “normal” one sample blood test on day 17 of her cycle doesn’t rule out a hormone imbalance. For example, some women have a shortened luteal phase and/or a less than ideal distribution of progesterone output throughout the second half of their cycle, and this can’t be measured through one sample testing.With that being said, doing a one sample blood test is usually much more cost effective. Although some natural healthcare professionals who utilize saliva testing will recommend a cycling hormone panel to all of their patients, I don’t recommend this test to everyone. If someone has issues such as infertility, ovarian cysts, uterine fibroids, or something else that might be caused by a hormone imbalance then I will usually recommend a cycling hormone test. Plus, it’s important not only to test for progesterone and estrogen (as well as DHEA and testosterone), but also the pituitary hormones FSH and LH.
- Urine test. Urine testing evaluates the metabolites of the hormones. This type of test usually requires a 24-hour urine collection, and metabolites can provide some valuable information with regards to estrogen metabolism, as well as methylation capacity. Some healthcare professionals will use it as a method of monitoring the effectiveness of bioidentical hormone replacement.
I’m very conservative when it comes to recommending bioidentical hormones, as while some people do need to take them, for many people they are unnecessary. When they are necessary to take, I don’t think urine testing is the best method for determining the effectiveness of bioidentical hormone replacement. So for example, if someone has low progesterone levels and decides to take natural progesterone, then I prefer to use saliva testing to determine the effectiveness of hormone replacement therapy. I do think that urinary testing for the hormones can come in handy to look at the estrogen metabolites, and this is especially true if someone has a family history of breast cancer.
Circulating estrogens are associated with an increased breast cancer risk (3) (4). Experimental and clinical evidence suggests that 16alpha-hydroxylated estrogen metabolites, which are biologically strong estrogens, are associated with breast cancer risk, while 2-hydroxylated metabolites, with lower estrogenic activity, are weakly related to this disease (5). Urine testing for the hormones looks at these metabolites, as well as the ratio of 2-hydroxyestrone to 16 alpha-hydroxyestrone, which once again may be associated with an increased breast cancer risk (6), as the lower the ratio, the higher the risk. However, there are some studies that show no relationship between this ratio and breast cancer (7).
At this point you might be somewhat confused and are still wondering “which method of testing the sex hormones is the best?” Well, different healthcare professionals will of course have different preferences, and of course it also depends on the person. So for example, someone who is in postmenopause obviously wouldn’t benefit from a cycling hormone panel or a one sample test two weeks apart. In my opinion a one sample serum or saliva test is usually the best option in this situation. And one can argue that it would be beneficial to look at the hormones through both the blood and the saliva in order to measure both the bound and free forms.
On the other hand, with cycling women I prefer a cycling hormone test, although since the test is expensive there are times when I will initially recommend a one sample blood test early in the second half of the cycle. Most medical doctors don’t utilize saliva testing for the sex hormones and thus only recommend blood testing. On the other hand, there are also doctors who recommend urine testing and feel that this is the most accurate method of evaluating the hormones. And so there is no consensus as to which method of testing is the best for cycling women, although I think it’s safe to say that a one sample test does not give a complete picture of what’s going on in an entire menstrual cycle, and therefore should not be relied on for a woman who has fertility issues or another health condition that might be related to an imbalance of the sex hormones.
So hopefully you have a better understanding of the different types of testing for the sex hormones. Although I frequently utilize saliva testing in my practice to measure the sex hormones, blood and urine testing can offer some benefits as well. But it really does depend on the situation, as while it’s fine to do a one sample saliva or blood test in postmenopausal women, this doesn’t give a complete picture of what’s going on with the hormones in cycling women. This doesn’t mean that a one sample blood test won’t provide any value in cycling women, but for a complete picture of what’s happening with the sex hormones in a cycling woman a cycling hormone panel is usually the best option.