Hormones & Your Menstrual Cycle

Written by

Elise Sutherland

Co-Founder FYR

Published 18 September 2023

Several screenshots of the Find Your Rhythm app displayed next to each other on a blue and pink gradient background

Key Takeaways

Hormones are essential to ensuring the functionality of your reproductive system.
Estrogen and Progesterone are the two key hormones thats drive your menstrual cycle.
Estrogen’s role is to thicken the endometrial lining (consists of blood and tissue in the uterus).
Progesterone’s role is to prepare your body for a potential pregnancy.

Role of Hormones

The menstrual cycle is regulated by the hormones estrogen and progesterone, which are produced by the ovaries. These hormones are essential for the proper functioning of your reproductive organs and enable pregnancy.

Role of Estrogen

At the beginning of a new menstrual cycle your estrogen levels will begin to rise and peak just before ovulation occurs.

The presence of estrogen stimulates the growth and proliferation of the endometrial lining (a mixture of blood and tissue) in preparation for a potential pregnancy.

Your estrogen levels will also see a slight rise (although less than the rise in the lead up to ovulation) during the early luteal phase. This spike is to help maintain and support your thickened endometrial lining, ensuring its receptivity for a potential implantation of a fertilised egg.

If fertilisation doesn’t occur, estrogen levels will begin to decline through the late luteal phase.

Role of Progesterone

During the menstrual cycle, progesterone is low until after ovulation. Then, progesterone becomes the dominant hormone and peaks in the middle of the luteal phase.

Progesterone stimulates further growth as well as changes the structure of the endometrial lining so that a fertilised egg can implant.

If conception does not occur, the corpus luteum (a temporary structure that forms in the ovary after ovulation occurs) starts to break down 9 to 10 days after ovulation, causing progesterone levels to fall which triggers the endometrial lining to shred and marks the start of a new menstrual cycle.

Top half of a phone on a light grey background showing the Find Your Rhythm interface with a calendar displaying the user's cycle

Find Your Rhythm
and work with your body, not against it.