Oestradiol (Ε2 or 17-β oestradiol)
Oestradiol is a steroid hormone, mainly produced in the gonads (ovaries and testes). It is one of the major oestrogens in women of reproductive age.
Men also produce oestradiol as a by-product of testosterone metabolism. Oestradiol levels in men generally fall in the same range as those of postmenopausal women.
Apart from its functioning as a sex hormone, oestradiol has a beneficial effect in other tissues such as bones.
Oestradiol, in women of reproductive age, is produced by granulosa cells within the follicles of female ovaries.
In males oestradiol is produced in lower levels, in the adrenal glands and testes.
Serum oestradiol measurement in women reflects primarily the activity of the ovaries. Serum oestradiol measurement during infertility treatment reflects follicular growth. Elevated levels of oestradiol and other oestrogens are correlated with oestrogen producing tumors. Elevated oestradiol levels also occur in precocious puberty.
Oestradiol and FSH blood tests are performed on the 2nd or 3rd day of the menstrual cycle in order to test the ovarian reserve. A normal FSH value (<10) may be mistakenly considered normal if oestradiol levels are high (>60pg/ml).