Quick answer: Estradiol is the main form of estrogen during the reproductive years. It regulates the menstrual cycle and supports bones, brain, heart and skin, and men need some estradiol too. Low estradiol is common in perimenopause and menopause; high estradiol can relate to PCOS, excess body fat, some medications or poor estrogen clearance. Timing in the cycle matters for interpretation.
Key takeaways
Estradiol is the main form of estrogen during the reproductive years and supports bones, brain, heart and skin.
Men need some estradiol too, so the right range depends on sex, age and life stage.
Low levels are common in perimenopause, high levels can relate to PCOS, body fat or slow estrogen clearance, and cycle timing shapes how a result is read.
What is Estradiol?
Estradiol (E2) is the most potent estrogen. In women it is made mainly by the ovaries; in men, smaller amounts are made from testosterone.
Why Estradiol matters
Estradiol matters for the menstrual cycle and fertility, bone density, and brain, mood and sleep. It also supports heart and blood vessel health, and skin and vaginal tissue.
Understanding your result
Reference ranges vary by lab, age and sex. Your provider interprets your result against the lab’s range and your overall picture, rather than chasing a single number. Functional labs are optional. They can be helpful in more complex cases.
What low Estradiol can mean
Low estradiol can reflect perimenopause and menopause, low body weight or over-exercising, or pituitary issues. In men, it can come with very low testosterone.
What high Estradiol can mean
High estradiol can reflect estrogen dominance relative to progesterone, PCOS or excess body fat, or some medications or hormone therapy. In men, it can come from higher aromatase activity with excess body fat.
What affects Estradiol
Estradiol is affected by cycle day, body fat, liver and gut clearance of estrogen, and alcohol and endocrine disruptors.
Ways to support healthy levels
Support estrogen clearance with fiber, cruciferous vegetables and limited alcohol (see estrogen dominance), and maintain a healthy weight while strength training. Reduce exposure to endocrine disruptors, and discuss hormone therapy options with your doctor if appropriate.
What does the research show about estradiol?
The Study of Women’s Health Across the Nation (SWAN) followed 3,302 women aged 42 to 52 with yearly blood tests and mapped hormone changes in 1,215 women who reached a natural final period. FSH began rising about 6.1 years before the final period, sped up about 2 years before it, and leveled off about 2 years after, while average estradiol did not change until about 2 years before the final period and then fell, stabilizing about 2 years after. Obesity softened and delayed the FSH rise. Because hormones were drawn only once a year, the study shows group patterns, not the day-to-day swings that make a single result hard to read in perimenopause. (Randolph et al., 2011)
In 2,311 SWAN participants followed with yearly bone scans, spine bone density fell by 5.6% over 4 years in women who went through natural menopause. FSH levels and how they changed over time predicted bone loss better than estradiol, and estradiol below 35 pg/mL was linked with lower bone density but yearly estradiol changes did not predict loss. The findings are associations and apply to women in the menopausal transition. (Sowers et al., 2006)
In a carefully controlled trial, 400 healthy men aged 20 to 50 had their own testosterone and estradiol temporarily suppressed and were given placebo or one of four testosterone doses for 16 weeks, with or without a drug that blocks conversion of testosterone to estradiol. Low testosterone mainly reduced lean mass, muscle size and strength, while low estradiol mainly increased body fat, and both contributed to lower sexual function. The 16-week design in young, healthy men may not reflect what happens with age. (Finkelstein et al., 2013)
Together, these studies show that estradiol matters for both women and men and that a single result is most meaningful when read with cycle timing, age and related hormones such as FSH.
Estradiol and healthy aging
Estradiol helps regulate inflammation, mitochondria, bone renewal and communication between tissues. As estradiol can decline in menopause, those systems often need more support. Related: menopause relief.
When to see a naturopathic doctor
It may be time to see a naturopathic doctor if you have irregular cycles, PMS or perimenopause symptoms, or fertility concerns. The same is true for men with breast tenderness or low libido, or if you want hormone results explained in context.
See a medical provider promptly for bleeding after menopause, very heavy bleeding, or a new breast lump.
Estradiol at a glance
| Topic | What the article explains |
|---|---|
| Why it matters | Menstrual cycle and fertility; bone density; brain, mood and sleep; heart and blood vessel health; and skin and vaginal tissue |
| What can affect it | Cycle day; body fat; liver and gut clearance of estrogen; and alcohol and endocrine disruptors |
| Supportive habits discussed | Support estrogen clearance with fiber, cruciferous vegetables and limited alcohol; maintain a healthy weight and strength train; reduce exposure to endocrine disruptors; and discuss hormone therapy options with your doctor if appropriate |
Questions to bring to your clinician
These questions can help you get the most out of your next visit.
On which cycle day was my estradiol drawn, and how does that change the way we read it?
What might my estradiol be telling us, given my health history and symptoms?
Which other labs would be worth pairing with my estradiol to get a clearer picture?
When would it make sense to recheck my estradiol, and what could I work on in the meantime?
Frequently asked questions
When should estradiol be tested?
In cycling women, timing matters. Your provider will choose the right cycle day.
What does low estradiol mean?
It is common in perimenopause and menopause and can also occur with low body weight or pituitary issues.
Do men need estradiol?
Yes, in small amounts for bones, brain and libido.
Can diet affect estrogen?
Fiber, cruciferous vegetables and less alcohol support healthy estrogen metabolism.
Sources
- Finkelstein JS, et al. Gonadal steroids and body composition, strength, and sexual function in men. N Engl J Med 2013. PMID: 24024838. https://pubmed.ncbi.nlm.nih.gov/24024838/
- Randolph JF, et al. Change in follicle-stimulating hormone and estradiol across the menopausal transition: effect of age at the final menstrual period. J Clin Endocrinol Metab 2011. PMID: 21159842. https://pubmed.ncbi.nlm.nih.gov/21159842/
- Santoro N. Perimenopause: From Research to Practice. J Womens Health (Larchmt) 2016. PMID: 26653408. https://pubmed.ncbi.nlm.nih.gov/26653408/
- Sowers MR, et al. Hormone predictors of bone mineral density changes during the menopausal transition. J Clin Endocrinol Metab 2006. PMID: 16403818. https://pubmed.ncbi.nlm.nih.gov/16403818/
- Teede HJ, et al. Recommendations From the 2023 International Evidence-based Guideline for the Assessment and Management of Polycystic Ovary Syndrome. J Clin Endocrinol Metab 2023. PMID: 37580314. https://pubmed.ncbi.nlm.nih.gov/37580314/
- MedlinePlus: Estrogen Levels Test
- MedlinePlus: Menopause
This article is for educational purposes only and is not medical advice. It does not replace an individual evaluation. Talk with your healthcare provider before starting supplements or changing medications, especially if you are pregnant, nursing, or managing a health condition.
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