Oestradiol: what it is, what it tells you and when it’s tested

Oestradiol is the main oestrogen, the female hormone made mostly by the ovaries. It regulates your cycle and helps keep your bones strong. Towards menopause the ovaries make less and less of it. Men have a little too: they make it from testosterone.

When it’s tested

Doctors order it when periods are irregular or stop, when a pregnancy is slow to come, or when they suspect an early menopause. In women it is usually done between day two and day four of the cycle, together with FSH. It is also used to follow fertility treatment.

Over 45 it is not needed to tell whether you are in perimenopause or menopause. Guidelines say not to use it for that: your symptoms and your periods are enough.

It is not a test for people who feel well, which is why Rosa does not test it. Instead it looks at what can change in the menopause years: LDL cholesterol, which tends to rise, ferritin if your periods are heavy, and vitamin D.

What it tells you, and what it does not

Read with FSH, oestradiol helps show where a cycle problem starts. If oestradiol is low and FSH is high, the ovaries are working less. If both are low, the brake often comes from the brain: stress, low weight, a lot of exercise.

On its own it says little. It changes a lot with the day of the cycle and, in perimenopause, from month to month. A single value does not say whether you are in menopause, or how many eggs you have left.

Early in the cycle a high oestradiol can hold FSH down and make it look normal. That is why the two are always read together.

That is why it is read together with other tests:

Normal oestradiol levels

There is no single normal value. In women oestradiol climbs to a peak before ovulation, then falls and rises a little again in the second half of the cycle. After menopause it is low. In pregnancy it rises a lot.

That is why every lab prints different intervals per phase: follicular, ovulatory, luteal and postmenopausal. The numbers also differ between methods. Read your value against the interval for the right phase, on your own report.

In men it is low and steadier. Check the unit too: some labs use pmol/L, which gives bigger numbers.

If your oestradiol is low or high

Symptoms of falling oestradiol

In the years around menopause, oestradiol falls and swings. This can bring:

Over 45, it is these symptoms, not the test, that tell your doctor you are in perimenopause. If they weigh on you, talk to your doctor: there are treatments that help.

What can skew the result

A few things change oestradiol without saying much about your ovaries. It helps to know them before your blood test.

When to worry

Talk to your doctor or gynaecologist if:

Frequently asked questions

What are normal oestradiol levels? They depend on the phase of the cycle, your age and the lab method. Your report prints an interval for each phase: read your value against the one for the phase you were in.

What are the symptoms of low oestradiol? Hot flushes, night sweats, vaginal dryness, irregular periods, changes in sleep and mood. They are the typical symptoms of the years around menopause.

Is oestradiol worth measuring at menopause? Usually not. Over 45, perimenopause and menopause are recognised from your symptoms and periods. If you take hormone therapy, your doctor adjusts it mainly on your symptoms.

What does a high oestradiol mean? Often nothing unusual: it is high before ovulation, in pregnancy and on hormone therapy. In perimenopause it can spike. If it is high for no clear reason, your doctor looks into it.

Why is oestradiol high in a man? Often because of excess weight: fat turns part of the testosterone into oestradiol. It can make the breasts grow. Talk to your doctor, who reads it together with testosterone.

Does Rosa test oestradiol? No. Rosa measures LDL cholesterol, ferritin and vitamin D, which are useful in the menopause years. If your doctor wants oestradiol, they order it separately.

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