Estradiol is a type of estrogen found in high quantities during a woman's reproductive life. This female sex hormone is secreted by the preovulatory follicle in the ovary.
Therefore, the highest level of estradiol occurs during ovulation, i.e., around day 14 of the menstrual cycle. In contrast, at the beginning of the menstrual cycle, blood estradiol levels are low because the ovarian follicle is not yet mature.
Read the full article on: Can a Woman’s Egg Count Be Measured with a Blood Test? ( 59).
By Concha Leal Cariñena M.D. (gynecologist), José María Sánchez Jordán M.D. (gynecologist), Marta Barranquero Gómez B.Sc., M.Sc. (embryologist) and Zaira Salvador B.Sc., M.Sc. (embryologist).
Last Update: 08/18/2025
