Oestradiol Progesterone and Prolactin Blood Test Kit

Oestradiol (also spelled estradiol and abbreviated as E2) is the most potent and biologically active of the three oestrogens (the others being oestrone and oestriol). In premenopausal women, oestradiol is primarily produced by the ovarian follicles, with smaller amounts from the adrenal glands and fat tissue. It's responsible for the development and maintenance of female reproductive organs, breast development, the menstrual cycle, and the preparation of the uterine lining for pregnancy. Oestradiol also has important effects throughout the body—it helps maintain bone density, supports cardiovascular health, influences skin elasticity and collagen, affects mood and cognitive function, and helps regulate body fat distribution. In women, oestradiol levels vary dramatically across the menstrual cycle. During the early follicular phase (days 2-5), levels are at their lowest baseline, typically 100-400 pmol/L. As the dominant follicle matures, oestradiol rises progressively, peaking at 400-1500 pmol/L (or higher) just before ovulation—this oestradiol surge triggers the LH surge that causes ovulation. After ovulation, oestradiol levels fall briefly then rise again moderately during the luteal phase before declining if pregnancy doesn't occur. This cyclical variation means that a single oestradiol measurement must be interpreted in the context of when in the cycle it was taken. As women approach menopause, oestradiol production becomes erratic. The ovaries contain fewer remaining follicles and produce oestradiol less consistently—some cycles may have near-normal oestradiol, while others are much lower. Eventually, after menopause, the ovaries essentially stop producing oestradiol, and levels drop to very low—typically below 100 pmol/L (often below 50 pmol/L). This dramatic decline causes the classic menopausal symptoms: hot flushes, night sweats, vaginal dryness, sleep disturbances, mood changes, and accelerated bone loss. Low oestradiol significantly increases the long-term risk of osteoporosis. In men, oestradiol is produced by conversion from testosterone via the enzyme aromatase, which is found in fat tissue, liver, brain, and other tissues. Normal oestradiol in men is typically 40-160 pmol/L—much lower than in premenopausal women but still essential for health. Adequate oestradiol in men supports bone density, libido, brain function, and cardiovascular health. However, excess oestradiol can cause problems: gynaecomastia (breast tissue growth), reduced libido, erectile dysfunction, emotional changes, and water retention. Men on testosterone replacement therapy need to monitor oestradiol because testosterone can convert to oestradiol—if levels become excessive, treatment adjustments or aromatase inhibitors may be considered. Results outside the normal range may need a follow-up with your GP.