The E2 test measures the concentration of estradiol in the blood serum, expressed in picograms per millilitre (pg/mL) or picomoles per litre (pmol/L). Reference ranges vary significantly by gender, menstrual cycle phase, and menopausal status, making clinical context essential for accurate result interpretation.
Normal ranges are 30 to 400 pg/mL in premenopausal women depending on cycle phase, with a mid-cycle peak of 150 to 750 pg/mL at ovulation, less than 30 pg/mL in postmenopausal women, and 10 to 40 pg/mL in adult men.
Normal for Phase and Gender
A result within the expected range for the specific cycle phase, menopausal status, or gender at the time of testing indicates appropriate E2 production. In women undergoing ovarian stimulation for IVF, E2 levels are interpreted in the context of the number and size of developing follicles rather than absolute reference ranges, with each mature follicle expected to contribute approximately 150 to 200 pg/mL to the total E2 level.
Low E2
A low E2 result indicates insufficient oestrogen production and may be seen in premature ovarian insufficiency, hypothalamic amenorrhoea from excessive exercise or low body weight, hyperpituitarism with FSH or LH deficiency, menopause, and in women on GnRH agonist therapy for endometriosis or uterine fibroids. In postmenopausal women, persistently very low E2 is associated with accelerated bone loss, cardiovascular risk, urogenital atrophy, and cognitive changes requiring clinical attention and possible HRT.
Elevated E2
An elevated E2 result may indicate ovarian hyperstimulation during fertility treatment, oestrogen-secreting ovarian tumours, exogenous oestrogen intake, advanced liver disease with impaired oestrogen metabolism, or obesity-related increased peripheral aromatisation. In men, elevated E2 is associated with gynaecomastia, reduced libido, erectile dysfunction, and suppression of testosterone production through negative feedback on the hypothalamic-pituitary axis.