Estrogen Levels Ovulation

As the dominant follicle develops, it secretes estrogen. The increasing but still estrogen levels provide negative feedback on LH and FSH. As estrogen is continually secreted in the late follicular phase, eventually, estrogen levels reach a high enough level that this feedback loop switches to positive, leading to a significant LH surge, which triggers ovulation.

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During the mid-luteal phase, estrogen levels rise again, though not as intensely as the initial spike. This rise is due to the formation of the corpus luteum, which secretes estrogen to maintain the endometrial lining for a potential pregnancy. If fertilization does not occur, estrogen and progesterone levels decline, triggering menstruation.

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No. Menstrual cycles vary widely in length and regularity across individuals. The chart offers a stylized representation of estrogen changes over an average cycle and should not be considered the sole normal pattern.

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