Hormones
Oestradiol
The most important female sex hormone; measured with cycle disorders, fertility testing and in men with breast development.
Everything about this testWhat it measures
In women, estradiol (E2) is made mainly in the maturing follicles of the ovaries, controlled by FSH and LH from the pituitary gland. It builds up the lining of the uterus and is responsible for the female body shape and strong bones. Men and women after menopause make a small amount in fat tissue, by conversion from testosterone. The value varies strongly with the cycle: low in the first days, high around ovulation.
- Ovarian failure (early menopause) in women under 40: low estradiol with high FSH
- Disturbed control from the pituitary gland or hypothalamus, for example with underweight, intensive exercise or stress: low estradiol with low or normal FSH
- Too much estrogen in men (breast development) due to overweight, medicines, anabolic steroids or, rarely, a tumor
- Monitoring during hormone treatment
High
In women, a high value around ovulation and during pregnancy is normal; outside those times, high values fit hormone treatment, IVF stimulation or overweight. A very high value without explanation is rare; an ovarian cyst can be the cause. Rarely: a tumor of the ovary. In men, a raised estradiol fits overweight, liver disease, anabolic steroids or testosterone treatment (part of it is converted into estradiol) and sometimes causes breast development. Rarely: a tumor of the testicle or adrenal gland.
Low
A low estradiol is normal in the first days of the cycle, during breastfeeding, with use of the pill and after menopause. In women under 40 without periods, a low estradiol with a high FSH may point to early menopause; with a low FSH it fits disturbed control due to underweight, an eating disorder, intensive training, stress or a problem of the pituitary gland. Symptoms that go with it: absent or irregular periods, hot flashes, a dry vagina and, in the long run, bone loss. A slightly low value in the menopausal transition years says little, because the value then fluctuates strongly from month to month.
Preparation
- Do you have a menstrual cycle? Then have your blood taken on day 2 to 5 of your cycle (day 1 is the first day of your period). Without a cycle, on the pill or after menopause the day does not matter.
- Do you take biotin (vitamin B8, often in hair and nail supplements)? Stop at least 2 days before the sample is taken, or 4 days for a high dose.
If your result is abnormal
The GP assesses estradiol together with FSH, LH, the cycle day and, if needed, prolactin and TSH. If early menopause is suspected, the measurement is repeated after a few weeks and a referral to a gynecologist follows; in men with a raised value, medicines, weight and liver function are looked at.
Reliability
A single estradiol can only be interpreted with the cycle day and together with FSH and LH. During the menopausal transition, estradiol and FSH vary strongly, so a measurement cannot diagnose menopause; according to the Dutch GP guideline (NHG) on menopause, it is diagnosed from symptoms and the menstrual pattern. With absent periods under the age of 40, FSH and estradiol do help to distinguish early menopause from disturbed control (NHG guideline on amenorrhea).
Limitations
- The cycle day: for a comparable result, blood is usually drawn on day 2 to 5 of the cycle (day 1 is the first day of the period); around ovulation the value is many times higher.
- The pill, hormone therapy, pregnancy and breastfeeding make the result unusable for assessing your own production.
- In men and in women after menopause, the values are so low that standard measurement methods are inaccurate; differences between laboratories are large.
- Biotin supplements can interfere with the measurement; stop biotin at least two days before the sample collection.
How common is this
Early menopause (ovarian failure before the age of 40) affects about 1 in 100 women. Natural menopause starts on average around the age of 51 and affects all women; a large share have symptoms. Breast development in men is usually harmless and mainly occurs during puberty, with overweight and at older ages.
Who is this useful for
Useful with absent or very irregular periods, especially under the age of 40, in fertility testing and in men with breast development or during testosterone treatment. For diagnosing menopause in women over 45 with typical symptoms, the test adds nothing, because the values vary strongly in those years. With use of the pill or hormone therapy, the result is not usable.
Downsides and risks
- Without the cycle day, the result cannot be interpreted: a normal peak around ovulation can be read as 'too high' and a normal value on day 3 as 'too low'.
- A single result in the menopausal transition years can give false reassurance or cause false alarm, because the value varies strongly from month to month.
Sources
Always discuss an abnormal result with your GP. If a result is strongly abnormal, we try to reach you as soon as possible. Read your result yourself as well and contact your GP if in doubt. A test does not make a diagnosis. Read more about risks and results