Sex Hormones 102: Understanding the Hormonal Cycle for Women

January 29, 2021

By Kate Moore

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The women’s hormonal cycle is complex. The 3 major hormones — testosterone, estrogen, and progesterone — change levels over the entire fertility cycle every month. If they get out of whack during each phase of the cycle, you can start getting some majorly nasty side effects like PMS.

Before we talk about the cycle, if you need a crash course on what these hormones are, you can pop over to this article to read up.

Hormonal Cycle Overview

The average hormonal cycle is 28 days, where “day 1” is the first day of your period. For most women, 28 days isn’t the timing. They can be shorter or longer, but 28 days is the “normal” count we typically use as an average or standard to make for easier conversation.

But despite the length of your cycle, each cycle has 2 phases: the follicular phase and the luteal phase, which are bookended by menstruation and ovulation.

The hormonal trends of the 2 phases can be seen in the chart above where the vertical line in the middle is ovulation. Let’s dive into what’s going on here…

Phase 1: The Follicular Phase

Menstruation kicks off the follicular phase and, on average, lasts 5 days. (Again, reported averages aren’t necessarily normal. Every woman is different.) The follicular phase ends at ovulation.

The chart below shows the hormone trend in the follicular phase where pink is estrogen, green is progesterone, and yellow is testosterone.

During your period, all of your sex hormones are low. This is a good phase for quiet “me” time and being around friends.

Over the next 5 days (after your period ends), estrogen starts rising, but is still relatively low. Testosterone also rises. This is a good time for cooperative work, and you may feel more creative and independent.

The subsequent 5 days lead up to ovulation. During this period, your estrogen starts to skyrocket and progesterone rises slowly. Romance and connection are the most satisfying in these days just before ovulation.

Phase 2: The Luteal Phase

Ovulation begins the luteal phase around day 15 of your hormonal cycle. During ovulation, your estrogen level is doubled, testosterone level is peaked, and progesterone level lies above testosterone but below estrogen. Ovulation also triggers the production of progesterone.

The luteal phase hormonal trend is shown in the second half of the chart below.

Over the couple of days immediately following ovulation, all 3 hormones return to a low baseline level. During the remainder of the luteal phase, progesterone levels are higher than estrogen, both peaking around days 20-22. The luteal phase is a good time for social interaction and “me” time. Schedule that spa trip or night out with the girls!

Taking Charge

Tracking your hormonal cycle with a fertility tracker can be super helpful. You can get all kinds of insights into how your specific cycle runs and be aware of what your hormones are doing. Once you’ve been tracking for a while, you can predict how you’ll be feeling when making plans or traveling.

Keep in mind things like traveling, stress, and hormonal birth control can affect your cycle. Hormonal birth control prevents ovulation, which typically results in low progesterone (and relative estrogen dominance) since ovulation is the trigger for progesterone production.

My Tool Bag

I use 2 tools to monitor my cycle. And if you’re thinking this is just for people looking get pregnant (or not!), it’s also for you. Whatever you’re doing and whatever your goals are, you’ve gotta know what’s going on in your body. It’s important to me to know what my body is doing so that I can plan accordingly. I plan my food, workouts, and social calendar around this thing.

The first is Daysy. Daysy is a thermometer that maps your temperature over your cycle with inputs for your period. It gives you a red, yellow, or green light to indicate fertility. If you use it to monitor fertility, it can indicate your fertility window with 99.4% accuracy once it’s seen a few cycles and knows your baseline. And in case you’re wondering whether you can trust something less than 100% accurate, the hormonal birth control pill is 91% effective with typical use (99% with perfect use) and condoms are about 85% effective (98% with perfect use).

I then input my Daysy temperature into the Kindara app. Kindara is free (and can be used successfully free), but they also have a subscription for $40/yr for more extensive tracking ability which I recommend if you want to take tracking seriously. Kindara gives a complete data set — not just temperature — for more accurate tracking, including customizable data points for things like mood, symptoms, exercise, and sleep.

Continue Reading…

Part 1: Sex Hormones 101 for Women

Part 3: How To Track Your Fertility Using Fertility Awareness Method

Continue The Conversation…

Follow me on Instagram @katemitchellmoore to join the community & conversation.

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This article is for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. These statements have not been evaluated by the Federal Food & Drug Administration. These information and products are not intended to diagnose, treat, cure, or prevent any disease.