What is estradiol?
Estradiol (also called E2) is the main form of estrogen in your body. It's primarily made by the ovaries, though small amounts come from fat tissue and the adrenal glands. Estradiol is the hormone most people mean when they talk about "estrogen."
It does far more than regulate your menstrual cycle. Estradiol helps protect your bones, supports cardiovascular health, keeps your skin elastic, plays a role in brain function and mood, and influences how your body stores and burns fat. It's one of the most powerful hormones in a woman's body.
Why it matters for longevity
Estradiol is deeply tied to long-term health. Before menopause, it acts as a natural shield — protecting against bone loss, heart disease, and cognitive decline. This is one reason why women tend to develop heart disease about a decade later than men on average.
When estradiol drops during perimenopause and menopause, that protective effect fades. Bone density decreases, cardiovascular risk rises, and many women experience changes in mood, sleep, energy, and body composition. Understanding where your estradiol levels stand gives you the information to take action — whether that means lifestyle changes, supplements, or a conversation about hormone replacement therapy (HRT) with your doctor.
What the numbers mean
Estradiol levels change dramatically depending on where you are in your menstrual cycle, and they shift significantly with age. Here are general ranges for premenopausal women:
- Follicular phase (days 1–13): 20–150 pg/mL
- Ovulation (around day 14): 100–400 pg/mL
- Luteal phase (days 15–28): 40–200 pg/mL
After menopause, estradiol typically drops to below 30 pg/mL — and often below 10 pg/mL. There's no single "optimal" number because the right level depends on your age, cycle phase, and individual health. What matters most is the pattern: are your levels appropriate for where you are in life, and are they supporting your symptoms and health?
If you're still menstruating, the best time to test estradiol is on day 3 of your cycle (the follicular phase), which gives a baseline reading. For women in perimenopause or menopause, timing is less critical.
What affects your estradiol
- Age and menopause: Estradiol naturally declines with age. The sharpest drop happens during perimenopause (usually starting in the mid-40s), leading to the low, stable levels seen after menopause.
- Body fat: Fat tissue produces estrogen. Women with very low body fat (such as some athletes) may have lower estradiol and disrupted cycles. On the other hand, excess body fat can lead to higher-than-optimal estrogen levels.
- Stress: Chronic stress raises , which can suppress estradiol production and disrupt your cycle.
- Exercise: Regular moderate exercise supports healthy hormone balance. But extreme or very intense training without adequate fueling can lower estradiol significantly.
- levels: DHEA-S is a precursor hormone that can convert into estradiol. When DHEA-S drops with age, it contributes to declining estrogen.
- Thyroid function: Your thyroid and reproductive hormones are closely connected. imbalances can disrupt estradiol levels, and the reverse is also true.
How to get tested
Estradiol is measured through a simple blood test. For premenopausal women, testing on day 3 of your cycle is standard for a baseline reading. Your doctor can order it, or you can use online lab services. If you're in perimenopause and experiencing symptoms like hot flashes, irregular periods, or mood changes, testing estradiol alongside FSH (follicle-stimulating hormone) gives a more complete picture.
How to improve it
- Maintain a healthy body composition. Both too little and too much body fat can throw estradiol off balance. A moderate, sustainable approach to nutrition and exercise supports healthy hormone production.
- Eat phytoestrogen-rich foods. Flaxseeds, soy (edamame, tofu, tempeh), and legumes contain natural plant compounds that gently support estrogen balance without overloading it.
- Manage stress. Since cortisol directly competes with reproductive hormones, keeping stress in check is one of the best things you can do for estradiol levels.
- Strength train. Resistance exercise supports hormonal health, bone density, and body composition — all of which interact with estradiol. Check your Biological Age to see how your overall health compares to your actual age.
- Talk to your doctor about HRT if appropriate. For women in menopause experiencing significant symptoms or health risks, hormone replacement therapy can restore estradiol to protective levels. The evidence supports its safety when started within 10 years of menopause, but it's a personal decision best made with a knowledgeable provider.