Oestradiol Blood Test

The Oestradiol Blood Test is a hormone test used to measure the level of oestradiol, the most biologically active form of oestrogen, in the bloodstream. Oestradiol plays a critical role in regulating the female reproductive system, as well as influencing bone health, mood, skin condition, and cardiovascular function. Although it is most commonly assessed in women, this test is also relevant for men, especially in the context of hormone imbalances, fertility concerns, or testosterone therapy monitoring.

Healthcare providers frequently use this test to evaluate menstrual irregularities, fertility issues, perimenopausal and menopausal status, and oestrogen-producing conditions. It is widely supported in clinical practice by gynaecologists, endocrinologists, and fertility specialists, in line with guidelines from the Royal College of Obstetricians and Gynaecologists and NICE (National Institute for Health and Care Excellence).

What Does It Test For?

The test checks for abnormal levels of oestradiol, helping to identify whether your oestrogen levels are within the expected range for your age, sex, and reproductive stage. In women, oestradiol levels fluctuate throughout the menstrual cycle and are used to assess ovarian function, egg development, or response to fertility treatments such as IVF. Low levels may suggest menopause, ovarian insufficiency, or hypothalamic amenorrhoea, while high levels can indicate oestrogen dominance, polycystic ovary syndrome (PCOS), or, in rare cases, hormone-secreting tumours. In men, elevated oestradiol can contribute to gynecomastia, infertility, or hormonal imbalance, particularly when testosterone levels are low.