Estradiol Levels Throughout the Menstrual Cycle

Phase-Specific Reference Ranges

The baseline hormonal state, when estradiol levels are at their lowest, represents a critical reference point for interpreting patient results, particularly in the early follicular phase 1
Estrogen rises progressively as the dominant follicle matures, with significant increases in estradiol levels during the late follicular phase 2
Peak estrogen levels typically occur on days 12-14, triggering the LH surge that induces ovulation, with estradiol levels ranging from 275-2864 pmol/L (approximately 75-780 pg/mL) 2
Estrogen levels rise again during the mid-luteal phase alongside progesterone, with estradiol levels ranging from 151-1941 pmol/L (approximately 41-529 pg/mL) 2
When estrogen levels recede, menstruation occurs, with estradiol levels ranging from 39-1769 pmol/L (approximately 11-482 pg/mL) during the late luteal phase 2

A patient's estradiol level can be normal or abnormal depending on the cycle day, highlighting the importance of timing in sample collection 1
To properly interpret estradiol results, it is essential to know the exact cycle day when blood was drawn, whether the patient has regular cycles, and any hormonal contraceptive use 1, 3

Estradiol levels below 20 pg/mL in premenopausal women warrant investigation for functional hypothalamic amenorrhea or ovarian dysfunction, according to clinical guidelines 4