PEAK TESTOSTERONE

Which Estradiol Test Is Best?

STEP 1:  Pull your estradiol with the best test available. (Always discuss everything with your doctor first.)

A lot of men (and physicians) do not realize that low and high estradiol can cause just as many of the classic symptoms that men deal with, such as erectile dysfunction, low libido, anxiety, depression, etc.

One big issue with men on HRT (Testosterone Therapy) is dialing in their estradiol to the correct level.  Nothing is quite as frustrating as finally convincing your physician to put you on testosterone, feeling better after he does and then finding out a few weeks later that all the benefits have gone.  You no longer feel as good; your libido has tanked; and your erectile strength is right back where it started. 

More often than not, the reason for this has to do with estradiol.  When a man goes on HRT, his estradiol rises and, in some men, it can go too high to the point where the extra estradiol cancels out the benefit of his newfound testosterone.  And, from what I've seen, this effect usually takes a couple of weeks to kick in.

After that, yet another estradiol problem can arise.  Many doctors and HRT clinics will put a man with high estradiol on an aromatase inhibitor - usually Arimidex - and some guys are quite sensitive to it.  Their estradiol crashes to an abnormally low level and they feel miserable.  Often their joints will ache with an accompanying loss of libido and erections. 

So getting estradiol tuned right is extremely important for a man on HRT and most clinics shoot for 20-35 pg/ml, although a few will go a little above or below that.  (This is controversial, so discuss with your doctor.)  Of course, estradiol is very important for men not on testosterone therapy, but, from what I've seen, very few doctors look at it.  You're lucky if you can get a blood draw for testosterone out of them much less one for estradiol!  (In the last year there have been two studies on the important of estradiol in HRT, so, hopefully, it will hit the mainstream doctors sometime soon.) 

CAUTION:  You have to be extremely careful in lowering your estradiol. If you go too low for too long, you can end up with osteoporosis. In addition, setting an estradiol target is more difficult now, because the big labs are no longer using the old assays but rather a more accurate technology called LC-MS/MS. However, this test lowered the range and so more research needs to be done to correlate the old versus the new values.

So how do you find out your estradiol level?  You just get a blood draw similar to testosterone, right?  Wrong!  Estradiol is much more problematic.  A man's estradiol levels are, of course, much lower than a pre-menopausal woman and so it's actually trickier to read our estradiol levels.  There are potentially 4 kinds of estrogen/estradiol-related tests.  Here in the U.S., Labcorp is the biggest lab and so we'll use them as an example:

  • 1. Estradiol (Regular) Test # 4515
  • 2. Estradiol, 140244  (Now LCMS) See this linkNOTE:  This is called the "sensitive" test, but this is a poor choice of words as "sensitive" has very specific meaning meaning in the testing and lab world.
  • 3. Estradiol, LCMS # 500108 (Also LCMS) See this link.
  • 4. Estrogens, Total # 4539
  • NOTE: To make matters more confusing, Quest has an "ultrasensitive test" that is actually the LCMS technology. So, again, you should probably get the test number from your doctor and research exactly what kind of test it is. I wouldn't go by the name. Get the actual number and look it up on the lab's site for verification. Remebmber that most of these tests you can get for yourself: Inexpensive Self-Testing Testosterone and Estradiol Labs.

    First of all, we will throw out #4 as this is just the wrong test, because it includes the other estrogens (estrone, estriol) in addition to estradiol.  However, I mentioned it, because I have seen (on the Peak Testosterone Forum) physicians who have mistakenly ordered this test.

    That leaves us with three legitimate candidates for male estradiol testing.  Here are the current ranges for an adult male for these LabCorp tests:

  • 1. Estradiol (Regular) Test # 4515:      ( 8-43 pg/mL)
  • 2. Estradiol, Sensitive Test # 140244:   (8-35 pg/ml and used to be 3-70 pg/mL!_
  • 3. Estradiol, LCMS # 500108
  • Again, let's look at a very practical example of what a man can run into and how it could potentially hurt his health if he does the wrong test. And thanks to Nelson Vergel and his great thread on the subject, where he and Dr. Crisler emphasize that the latest technology is LCMS (which actually stands for Liquid Chromatography/Tandem Mass Spectrometry, i.e. LC/MS-MS).  This is pretty clearly the best technology, because it has the least cross-reactivity.  Cross-reactivity is where you are measuring for compound X, but you pick up a percentage of other proteins, hormones, etc. as well.  This is exactly a situation that you do NOT want, because it overestimates estradiol.

    Regular Versus Sensitive Labcorp Test

    NOTE:  The information below is outdated, but I am including it for men in other countries.  Basically, Labcorp has two other assays, one is now defunct, and the other is inaccurate due to the above cross reactivity issue.

    Now let me go to some comparisons of Labcorp's Sensitive Test versus their regular test.  And the reason I am doing this is to emphasize that, at least in my opinion, the regular estradiol test is not very safe or accurate in many situation and illustrate that with some practical lab results.  As an example, one of our forum posters has actually had both of these estradiol tests pulled on the same day and same time and here are his results:

  • #4515     Labcorp Standard 7-43 pg/mL ---> 334 Labcorp "Sensitive"  3-70 pg/mL ---> 19
  •   NEWS FLASH: These results are no longer valid as this test has now changed to LCMS.

    The first thing to notice is that he was easily in the range of both tests. Therefore, both tests should have provided reasonably accurate results. Yet there is a 73% difference! The standard test is almost double the value of sensitive test.

    And here is what is so dangerous:  estradiol too high or too low has been shown in several studies to be dangerous to a man's health, due to (primarily) increased cardiovascular risks.  Therefore, if you choose the wrong test, you could potentially be putting yourself at risk for heart disease or stroke.  Life Extension Foundation sites studies that show:

    "The men in the balanced quintile�with the fewest deaths�had serum estradiol levels between 21.80 and 30.11 pg/mL. This is virtually the ideal range that Life Extension� has long recommended male members strive for. The men in the highest quintile who suffered 133% increased death rates had serum estradiol levels of 37.40 pg/mL or above. The lowest estradiol group that suffered a 317% increased death rate had serum estradiol levels under 12.90 pg/mL." [1]

     Even worse in many cases, is the fact that low estradiol can easily slowly lead to osteopenia and eventually osteoporosis, a potentially crippling and painful condition.  Look at the man's standard reading above of 33.  His doc could potentially decide to put him on some Arimidex (if he was on HRT) to get him closer to 20 pg/ml.  Yet, using the sensitive test, he would probably have estradiol of 12 or 13!

    Making matters worse is the fact that many doctors are trying to save money by using the less expensive standard test and think to themselves, "Well, my patient is probably in range, so this is fine." 

    Here is an example from another forum poster.  In this case, his doctor used the lab's sensitive test and he the same morning pulled the regular estradiol test.  His numbers, which includes total testosterone, were:

    Total Testosterone=1080; Estradiol regular = 34.8  pg/ml

    Sensitive: TT=1252; Estradiol sensitive = 25 pg/ml

    Again, notice the identical pattern:  he is in range more than likely on both tests but the regular estradiol test reads significantly higher (40%) than the sensitive.  Since that time we have had several other posters end up with similar results.

    The important things:

  • Stay in range for any lab test you do.
  • The gold standard should probably be the LCMS technology, but you will probably find some knowledgeable doctors still using the sensitive test.  Deciding on the best test is something, in this case, that you have to do with your physician, but make sure that he/she is knowledgeable and not just prescribing the cheaper test to save money.