Estradiol on the fifth day of menstruation is usually 94-433 pmol/L normal. Estradiol is mainly produced by the ovaries in fertile women, and in pregnant women it is mainly produced by the ovaries, placenta and to a lesser extent by the adrenal glands. During the normal menstrual cycle, estradiol fluctuates with the ovarian cycle. During the follicular phase, estradiol levels are relatively low, with reference values of 94-433 pmol/L. As follicles recruit, especially the growth of dominant follicles, estradiol levels will gradually rise and reach a peak at the ovulatory phase, with reference values of 704-2200 pmol/L. If estradiol is produced on the fifth day of the menstrual cycle, it is mainly produced by the ovaries and the placenta. If the value of estradiol on the fifth day of menstruation is abnormal, it is recommended to go to the hospital in time and follow the doctor’s instructions for treatment to avoid delaying the condition.