Oestradiol

Women: 46 to 607 pmol/L · Men: 28 to 156 pmol/L

In women it depends on the cycle phase (about 46 to 607 pmol/L in the first half, 315 to 1830 around ovulation, 160 to 775 in the second half) and is low after the menopause (below about 200), while men run at roughly 28 to 156, and assays differ at low levels.

Oestradiol is the main oestrogen, made mostly by the ovaries in women before the menopause and in smaller amounts by fat tissue, the adrenal glands and the testes. It builds the womb lining each cycle, supports bone, and its rise and fall shape the menstrual cycle. Men make a little of it from testosterone.

It is requested for irregular or absent periods, the menopause and HRT questions, fertility treatment where it is tracked closely, and in men with breast tissue enlargement or in some testosterone assessments. Private wellness panels often include it.

• The middle of the menstrual cycle, around ovulation
• Pregnancy
• HRT and the combined contraceptive pill, depending on the type of oestrogen used
• Fertility treatment that stimulates the ovaries
• Ovarian cysts and, rarely, oestrogen-producing tumours
• Heavier body weight and liver disease in men
• Some medicines and anabolic steroids in men, through conversion to oestrogen

• The menopause and the years leading up to it
• Low body weight, heavy exercise and eating disorders
• The first few days of the cycle, when it is naturally at its lowest
• Some medicines, including aromatase inhibitors and GnRH analogues
• Ovaries that are working less well, from any cause
• Pituitary or hypothalamus problems, which are uncommon

• The value depends heavily on the day of the cycle it was taken
• Standard assays are unreliable at the low levels seen after the menopause and in men, so values there vary between labs
• Some HRT types (for example ethinylestradiol, or conjugated oestrogens) are not measured by the assay at all, so the value can look low on treatment

In women the cycle day should be recorded, and with FSH and LH the sample is often taken on day 2 to 5. Time of day matters little. For men and postmenopausal women a mass spectrometry method gives more reliable low values.

Written by a UK consultant physician. Typical UK adult reference ranges; your laboratory's own printed range takes precedence.