Dr. Melissa McRae, CEO, Founder of Vitality Natural Wellness and Medspa
Estrogen — the unseen superhero of your system. Do you know her? She affects almost every system of your body from your brain to your skin to your moods and to your menstrual cycles.
If you don’t, it’s time you get acquainted! Let’s explore how estrogen functions during month-to-month fluctuations that create a menstrual cycle.
Estrogen’s Role in the Menstrual Cycle
Estrogen is like a symphony conductor leading an orchestra of bodily functions within a woman’s body. Although it comes primarily from the ovaries, this hormone can also be found in smaller amounts in the adrenal glands and fat tissue. Estrogen naturally guides a woman’s body to prepare for a potential pregnancy with each cycle. It also influences growth and development, brain health and mood, and supports bone health to name a few things.
Imagine the menstrual cycle as a hormonal symphony where estrogen takes center stage. At the beginning of the cycle, estrogen levels rise, signaling the body to prepare for a potential pregnancy. It stimulates the thickening of the uterine lining (called the endometrium), making it ready to nourish a fertilized egg. Meanwhile, in the ovaries, estrogen helps eggs mature and develop.
Cue Ovulation
Midway through the menstrual cycle, estrogen holds the key that unlocks the door to ovulation. Estrogen rises and triggers the brain to tell the ovaries to send out an egg. This process is known as ovulation, where the egg travels down the fallopian tube, waiting for a potential sperm to fertilize it. The destination for this mature egg is the uterus, and estrogen is the hormone that prepares the uterus for its guest.

Think of the uterus as a cozy house that is well-prepared for its guest. Estrogen helps create a warm, welcoming environment by increasing blood flow to the uterus and thickening the uterine lining. If fertilization doesn’t occur, estrogen levels decrease, signaling the body to shed the thickened lining. This results in menstruation, commonly known as a period. Afterward, a new cycle begins and estrogen levels rise once again, starting the process over.
Onto Menopause
Most women have a menstrual cycle monthly and estrogen regulates this pattern. As women get older, the ovaries stop making estrogen. After a year without a menstrual cycle, the woman enters a new phase called menopause. This phase is characterized by a lack of estrogen–no signal, no uterine changes, and the musical symphony that estrogen creates slowly comes to a halt. This phase is another conversation but keep in mind–estrogen is the key!
Our internal hormone estrogen is an unseen hero to most women. This hormone specifically orchestrates the menstrual cycle as one of its crucial functions. Like a conductor leading an orchestra, it plays a vital role in preparing the body for potential pregnancy and maintaining overall health. Understanding the role of estrogen is helpful when we talk about the changes that occur in your body during these monthly cycles. It is a complex symphony, and when it is properly functioning, the body thrives!