In this article:
- What is estradiol?
- Estradiol vs. estriol vs. estrogen
- What are normal estradiol levels?
- How are estradiol levels tested?
- Testing your estradiol from home
Estradiol may be an unfamiliar name to many, but getting it tested can still tell you a lot about your state of health, especially where hormonal balance is concerned.
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Takeaways:
- Estradiol and estriol are both forms of estrogen; the average estrogen test will typically test estradiol, which is the strongest form of estrogen.
- Getting an estradiol test is fairly easy, but interpreting it can be a bit more complicated because of the many factors that influence estradiol levels (especially in women).
- Since estradiol has such a huge impact for both men and women, having it tested is a smart move if you’re trying to learn about your hormonal health.
Before getting started, a quick note: when Base uses gendered language we’re talking about physiological gender assigned at birth, not someone’s preferred pronouns.
What is estradiol?
When people talk about estrogen, they’re usually talking about estradiol - it’s that simple. Also referred to as E2, it’s the most potent member of the estrogen family.
The majority of the body’s estradiol is produced by the ovaries in women, and by the testicles in men (it’s a little more complicated for males, but that’s beyond the scope of this discussion). We’re actually exposed to estradiol from the earliest stages of embryonic growth - it’s thought to influence the development of neural circuits that govern sex-typical behaviors, such as aggression and social instincts.
Estradiol doesn’t slow down once you’ve exited the womb - not even close. After it’s helped the infant’s brain develop, it plays a role in the growth of the reproductive system and secondary sex characteristics. You know all the changes that happen during puberty? Estradiol is responsible for a lot of that, especially in female biology.
It doesn’t stop at puberty, though - estradiol plays a huge role in the menstrual cycle, as well as in male sexual health. Without appropriate estradiol levels, women would be unable to ovulate, menstruate, or have a healthy pregnancy, and men couldn’t get or maintain an erection.
As important as sexual functions are, estradiol is essential for even more than that. It’s instrumental in maintaining healthy bones, skin, hair, pelvic muscles, mucous membranes - even your heart benefits from estradiol! This is one of those biomarkers that you really want to be balanced, because when it isn’t, pretty much your entire body is affected.
Estradiol vs. estriol vs. estrogen
Time to dive into the details, folks! If it seems complicated now, hopefully won’t in a couple of minutes.
- Estradiol is the main player when you’re looking at estrogens. Not only is it present in higher amounts than the other forms of estrogen, but it’s also stronger. It’s crucial for maintaining a healthy libido, ensuring vaginal development and lubrication, stimulating the growth of egg follicles in the ovaries, maintaining the lining of the uterus, stopping lactation after a baby has been weaned, governing fat distribution, and so much more. And that’s just what it does for women! For men, it’s involved in a few of the same things, such as sex drive and fat distribution, but it’s also necessary for sperm production and erection quality.
- Estriol (a.k.a. E3) is another member of the estrogen family; it’s still quite important for maintaining hormonal balance, but it’s a lot weaker than estradiol. Instead of being manufactured in the ovaries, it’s mainly produced by breast tissue and by the liver. It doesn’t experience the same spikes and drops as estradiol, except during pregnancy, when it goes through the roof. We don’t know as much about estriol as we do about estradiol, but it’s hypothesized that it actually modulates the effects of its stronger cousin - mainly because it seems to compete with estradiol for the same hormone receptors. After observing how estriol affects female health during pregnancy, there seems to be an emerging connection between estriol and improved immune function against inflammatory, autoimmune, and neurodegenerative conditions. Not bad for the weakest estrogen in the bunch, right?
- Estrogen isn’t actually a single hormone, but a family of hormones. It would actually be more appropriate to say “estrogens”, since…that’s actually what it is. As mentioned above, when “estrogen” is discussed, estradiol is probably the specific estrogen that’s being referred to. Here’s an example: estrogen levels naturally fluctuate during the menstrual cycle, rise sharply during pregnancy, and fall during and after menopause. While that’s technically correct, the sentence is actually describing estradiol specifically - that’s exactly what estradiol, not estrogen per se, does at various stages in the female body. Let’s be real, though - simply saying “estrogen” probably makes more sense in most cases, even if it isn’t 100% accurate.
What are normal estradiol levels?
Before talking numbers, it’s important to understand what it means to discuss “normal” levels of any biomarker, whether it’s a hormone, vitamin, or mineral. First of all, you have the reference ranges that outline minimum and maximum values of the biomarker in question in healthy people. If you’re following a cut-and-dried approach to interpreting your state of health, getting a test result that falls within the reference range could be the end of the story. Let’s say you’ve been experiencing symptoms of low estradiol, but you’re still within the appropriate reference range below:
- In premenopausal women: 15 to 350 pg/ml
- In postmenopausal women: below 18 pg/ml
- In pregnant women: 188 to 7192 pg/ml, up to 20,000 pg/ml in some cases
- In men: 10 to 40 pg/ml
So what’s up with your hormones? Even though reference ranges can describe what “normal” looks like for a general population, they can’t say what’s “normal” for you specifically. Here’s an example: a 49-year-old woman starts experiencing vaginal dryness, loss of libido, and an increase in food cravings, so she assumes that she’s entering menopause. She visits her doctor, he orders some tests, and the results show that she’s well within the reference ranges for pre-menopausal women. But wait - she’s already experiencing symptoms of major hormonal changes, so why would the test show that everything’s normal?
There’s the catch - her hormones aren’t normal for her. If for some reason she’d established a baseline for her hormones earlier, she probably would have seen her levels dropping below normal as she approached menopause.
Signs of high estradiol
- Swollen or tender breast tissue
- Loss of libido
- Headaches
- Mood swings
- Weight gain
- Disrupted sleep patterns
- Fatigue
- Infertility
- Irregular periods in women
- Erectile dysfunction in men
Signs of low estradiol
- Tender breast tissue
- Thinning urethra, resulting in an increase of UTIs
- Lack of vaginal lubrication
- Hot flashes
- Headaches
- Depression
- Fatigue
- Brain fog
- Irregular periods in women
- Erectile dysfunction in men
How are estradiol levels tested?
There’s nothing terribly flashy about an estradiol test - some of your blood is drawn, and then the amount of estradiol in it is measured at a certified lab. If you’re doing the test at home, don’t worry - you won’t have to draw your own blood! In that case, all you’ll need to do is a simple finger-prick test.
If you’re a person without a menstrual cycle, you won’t have to worry about what time of the month to take an estradiol test - it should be pretty uniform aside from minor daily fluctuations. If you do menstruate, though, you’ll probably be asked to take the test on the third day of your menstrual cycle (with day one being the day your period starts). This is because women experience pretty drastic monthly fluctuations in estradiol; if they got tested without being able to tie the results to a specific part of the menstrual phase, it wouldn’t be as informative as it could be. Testing progesterone levels alongside estradiol is also helpful, since the estradiol-progesterone ratio is almost as important as the levels themselves. If you aren’t sure whether or not you’re keeping to your typical baseline, seeing the ratio of the two hormones can tip you off to a potential imbalance.
Testing your estradiol from home
Measuring your estradiol levels through at-home testing is a great way to keep on top of your hormonal health. Not only do you get to skip the vials of blood in favor of a finger-prick test, but you also avoid having to convince a doctor to order tests without evidence of dramatic hormonal imbalances. Base’s sex drive test panel will even show your estradiol and progesterone side-by-side, which is especially handy if you’ve never tested either one before. And since at-home lab tests have been shown to be just as accurate as anything a doctor would order, you can feel confident in what your test results reveal.
Knowledge is power, as they say, and that applies just as much to your hormonal balance as to anything else. If you can start learning about the ins and outs of your hormones - starting with the big ones, like estradiol - you’ll have the tools you need to take charge of your health and improve your life!
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