Oestradiol Blood Test

• Oestradiol (measured): the level of oestradiol (E2) in serum at the time of the sample.

This test does not measure oestrone, oestriol, FSH, LH, progesterone or SHBG. In women under 40 with suspected premature ovarian insufficiency, NICE bases diagnosis on FSH, so oestradiol on its own cannot answer that question. Our female hormone profile includes FSH, LH and oestradiol together.

There are three main oestrogens. Oestradiol (E2) dominates during the reproductive years. Oestrone (E1) becomes the main form after the menopause and is made largely in fat tissue and from adrenal hormones. Oestriol (E3) is produced mainly by the placenta in pregnancy.

In the first half of the menstrual cycle, follicle-stimulating hormone (FSH) from the pituitary gland stimulates ovarian follicles, which release increasing amounts of oestradiol. The rising level thickens the womb lining and, at its peak, helps trigger the surge of luteinising hormone that leads to ovulation. Oestradiol rises again in the luteal phase alongside progesterone, then falls before a period.

As ovarian follicles run down in the years before the menopause, oestradiol becomes erratic and eventually settles at low levels. Falling oestrogen feedback is the reason FSH rises after the menopause.

In men, oestradiol comes partly from the testes and adrenal glands and partly from conversion of testosterone in body tissues. It contributes to bone health and body composition. In the blood, oestradiol is carried largely by sex hormone binding globulin (SHBG) and albumin.

Clinicians measure oestradiol when investigating menstrual problems, suspected early menopause in women under 40, early or delayed puberty, gynaecomastia and rare oestrogen-producing tumours. Serial measurements are also used by fertility clinics to monitor follicle development during IVF.

Reference ranges for oestradiol are wide because levels vary with cycle phase, age and sex. As an example, one NHS laboratory quotes 72 to 529 pmol/L for women aged 11 to 55, up to 118 pmol/L for women over 55, and up to 146 pmol/L for adult men. Our partner laboratory's ranges will be printed on your report and may differ.

The same NHS laboratory notes that because oestradiol fluctuates from day to day, a single measurement is rarely useful and FSH is a more reliable guide to ovarian function. Lab Tests Online UK adds that diagnosis is never based on one oestradiol result and that trends over time are more informative.

Why results can mislead

• Cycle timing: a sample just before ovulation can be several times higher than one taken during a period.
• Perimenopause: levels can be high one week and low the next, so a normal or even raised result does not rule out perimenopause.
• Hormone medicines: HRT, hormonal contraception and fertility drugs all change results, and different products affect the test in different ways.
• Other conditions: liver or kidney impairment can alter results.
• Laboratory method: results from different methods and laboratories are not always interchangeable, so compare repeat results from the same laboratory where possible.

Persistently absent periods, periods stopping before 40, or breast enlargement in a man should be assessed by a GP whatever the result shows. With your consent we can write to your GP with your results.

For women aged 45 and over with typical symptoms, NICE recommends diagnosing perimenopause and menopause on symptoms and periods alone, without blood tests, and specifically lists oestradiol among tests not to use. Between 40 and 45, NICE suggests an FSH test may be considered. Under 40, premature ovarian insufficiency is diagnosed from symptoms plus raised FSH on two samples taken four to six weeks apart, never from a single test.

Oestradiol is more useful when your GP or specialist wants a specific piece of information: confirming that oestradiol is low in someone whose periods have stopped, assessing gynaecomastia in a man, or checking a level while you use oestradiol patches, gel or an implant. Lab Tests Online UK notes that HRT monitoring by blood test applies to these routes rather than to tablets.

May be useful if you

• are under 45 and your periods have become irregular or stopped, and you want a result to discuss with your GP
• have been asked by your prescriber for an oestradiol level while using patches, gel or an implant
• are a man being assessed for breast tissue enlargement

May not be the right choice if you

• are over 45 with typical menopausal symptoms and want to confirm the menopause: NICE advises against using oestradiol for this
• are having fertility treatment: oestradiol monitoring is timed and interpreted by your fertility clinic
• are pregnant
• want a single test to confirm premature ovarian insufficiency: this needs FSH on two occasions

A new breast lump in anyone, including men, should be checked promptly by a GP rather than investigated with a blood test.

• Established use: oestradiol testing supports the assessment of menstrual problems, early menopause under 40 and gynaecomastia, interpreted with FSH and clinical findings.
• Physiology: the fall in ovarian oestrogen around the menopause is a normal stage of life and contributes to symptoms such as hot flushes and to changes in bone over time.
• Limits: NICE bases menopause diagnosis and treatment decisions in women over 45 on symptoms, so an oestradiol level does not decide whether HRT is appropriate.
• Unproven: there is no established "ideal" oestradiol level for healthy ageing, and no evidence that a single result predicts longevity.

• Cycle timing: if you have periods, note the first day of your last period. If your GP or specialist has asked for a sample on a particular cycle day, book for that day.
• HRT or contraception: tell us the product, how you use it (tablet, patch, gel, spray or implant) and when you last took or applied it. Do not stop or change any prescribed medicine for this test.
• Men: oestradiol varies much less through the day than testosterone, so timing is less critical. If you are also testing testosterone, a morning sample suits both.
• Biotin: mention any biotin or hair, skin and nail supplement when booking, as high doses can affect some hormone tests.

Choose how your sample is taken when you book. We confirm the collection option, any collection fee and the expected turnaround time before you book.

• Juvenology Clinic, Maidstone (82 King Street, Maidstone ME14 1BH): Available.
• Partner clinic near you, anywhere in the UK: Available on request. We confirm availability for your postcode before you book.
• Postal home finger-prick kit: Ask before ordering. We offer a home kit only where the laboratory confirms this test is suitable for a finger-prick sample.

Sample: Venous blood sample (serum); finger-prick suitability confirmed by the laboratory

Collection notes: Record the first day of your last period, or book the cycle day your clinician requested. If you use HRT or hormonal contraception, note the product, route and when you last used it.

The price of this test covers laboratory analysis and the laboratory's results report. The report lists each result beside the laboratory's reference range.

Beyond the blood test: optional support, priced separately

• Personalised written interpretation report: £50
• General consultation: £50
• Results consultation (results discussion and follow-up advice): £100
• Personalised programme: from £150, after we assess whether a programme suits you

Consultations are with Marina, an NMC-registered nurse. She explains what your results show and how they relate to lifestyle. No prescription service is offered with these tests.

If a result suggests you need medical follow-up, we will recommend that you see your GP and, with your consent, can provide a letter to take with you. A blood test cannot rule out every condition. If you have symptoms, speak to your GP or NHS 111, and call 999 in an emergency.

Can this test tell me whether I am in the menopause?

Not on its own. For women over 45, NICE recommends diagnosis based on symptoms and periods, and advises against using oestradiol. Under 45, FSH and a GP review are needed.

Which day of my cycle should I test?

Follow any instruction from your GP or specialist. Otherwise, record your cycle day so the result can be compared with the right part of the range.

Why did two results a few weeks apart differ so much?

Oestradiol changes across the cycle and can fluctuate sharply around the menopause. This is expected and is why one result is rarely decisive.

Is this test useful for men?

It can be, mainly when a GP is assessing breast enlargement or a hormone problem. It is usually interpreted with testosterone and other hormones.

Can I use this test to check my HRT dose?

Only your prescriber can decide whether a level is needed and what it means for your treatment. Please do not change your HRT based on this result.

Is interpretation of my result included?

The price covers laboratory analysis and the laboratory's report with reference ranges. You can add a personalised written interpretation report (£50) or a results consultation (£100).

1. Menopause: identification and management (NG23). National Institute for Health and Care Excellence. https://www.nice.org.uk/guidance/ng23/chapter/recommendations
2. Oestrogen. Lab Tests Online UK. https://labtestsonline.org.uk/tests/oestrogen
3. Oestradiol: test information. University Hospitals of North Midlands NHS Trust Pathology. https://www.uhnm.nhs.uk/hospitals-and-services/pathology/tests/oestradiol/
4. Sex Hormone Binding Globulin (SHBG). Lab Tests Online UK. https://labtestsonline.org.uk/tests/sex-hormone-binding-globulin-shbg
5. The effect of diurnal variation on clinical measurement of serum testosterone and other sex hormone levels in men. Journal of Clinical Endocrinology & Metabolism, 2009;94(3):907–913. https://doi.org/10.1210/jc.2008-1902
6. Li D, et al. Association of Biotin Ingestion With Performance of Hormone and Nonhormone Assays in Healthy Adults. JAMA, 2017;318(12):1150–1160. https://doi.org/10.1001/jama.2017.13705