Knowledge is Empowering: Understanding The Menstrual Cycle
Time to talk about a traditionally taboo subject: menstrual cycles. For many people, menstrual cycles and the hormones involved are only associated with PMS and periods. However, no matter what hormones you have, they’re constantly impacting us. Knowledge about our bodies is empowering. By recognizing patterns in how we feel during different phases, we can be better equipped to adapt to these changes throughout each month. Whether you personally experience menstrual cycles or not, knowing how hormone cycles affect those of us who do, can give us a greater understanding of ourselves and those we care about.
In this article, I will give a brief overview of what is happening physiologically during each phase of the menstrual cycle, as well as how each phase may make the person experiencing it feel. There is also a glossary of hormone terms at the end of the post.
Disclaimer: Textbooks often use a 28 day cycle when describing the menstrual cycle. However, a normal cycle can be 21-35 days depending on the person. For simplicity sake, I use the 28 day cycle in my description below but everyone is different. If you are concerned about the length of your cycle please speak with your healthcare provider. Traditionally, day one of the cycle is considered for the first day of a period. Additionally, the description below describes those who are naturally cycling. Hormonal birth control often suppresses the menstrual cycle (more on this in a future post).
From: University of California San Francisco. (n.d). Normal menstrual cycle. Center for Reproductive Health. Accessed March 31, 2025. https://crh.ucsf.edu/about-fertility/normal-menstrual-cycle
Follicular Phase (Days 1-14)
Physiologically what’s happening:
At the start of a period both progesterone and estrogen are low. After a period ends, ovaries start gradually increasing the release of estrogen.
Follicle-stimulating hormone (FSH) tells ovarian follicles, which contain eggs, to start maturing the eggs for release. The uterine lining begins to thicken again.
Throughout the follicular phase, estrogen is higher than progesterone.
Eventually estrogen levels peak along with FSH and luteinizing hormone (LH) which then leads to the next phase: ovulation.
How this impacts you:
During the follicular phase, especially after the first 1-3 days of a period, menstruating people may feel higher energy levels, elevated moods, increased confidence levels, and be more social thanks to estrogen’s relationship with serotonin.
It might feel easier to be productive and easier to exercise more intensely. It’s also easier to sweat.
Sticky yellow or white cervical discharge occurs after the end of a period and then becomes creamier and wetter closer to ovulation.
Ovulation (Day 14)
Physiologically what’s happening:
Ovulation occurs shortly after estrogen, FSH, and LH peak.
One dominant follicle that has been maturing swells up and then LH tells the follicle to burst, releasing an egg.
The egg moves into the fallopian tube after ovulation where it could get fertilized. The follicles that did not release an egg get reabsorbed by the ovaries.
Ovulation is important whether or not someone wants to get pregnant because it is how the body makes progesterone. Ovulation is like an on or off switch, there is no halfway ovulation. Either a period or a pregnancy will occur after ovulation.
How this impacts you:
Some people can feel a mild stab of pain on the side of their pelvis when the egg is released. This is called mittelschmerz.
Egg-white like cervical fluid is released a few days before ovulation.
In this phase, menstruating people often report higher libido, greater openness to trying new experiences, elevated moods, and feeling more attractive.
Luteal Phase (Day 15-28)
Physiologically what’s happening:
The empty follicle from ovulation becomes the corpus luteum, a gland that releases progesterone.
Without ovulation there is no corpus luteum. The lifespan of the corpus luteum will decide how long the luteal phase lasts, normally 10-16 days. If pregnancy occurs progesterone secreted by the corpus luteum nurtures the pregnancy. If no pregnancy occurs, the corpus luteum breaks down and progesterone levels decrease.
Overall, progesterone is higher than estrogen in the luteal phase.
And, both estrogen and progesterone are cumulatively higher in the luteal phase compared to the follicular phase. During the luteal phase, estrogen and progesterone peak approximately 5 days before your period starts. If no fertilization and implantation occurs, these hormones start declining, reaching their lowest point around the time your period starts.
How this impacts you:
Progesterone becomes allopregnanolone, a neurosteroid which calms the nervous system. Increased relaxation, improved sleep, and greater fatigue often happen right after ovulation.
Because progesterone also increases body temperature and makes it more difficult to sweat, people often feel hotter during the luteal phase.
However, once estrogen and progesterone start decreasing during the luteal phase what we think of as “PMS” symptoms might occur.
Estrogen and progesterone interact in the body in ways that might cause bloating, fatigue, acne, increased appetite, breast tenderness, lower moods and feeling less social. Prostaglandins, which contribute to cramps on the days before a period, can also act on the GI system, causing GI symptoms. Ways to manage PMS symptoms coming in a future post!
There is usually very little cervical fluid discharged during this time.
Disclaimer: Severe PMS symptoms may be a sign of PMDD or other underlying issues. Please speak with your healthcare provider if your PMS symptoms are causing you distress.
Menstruation (Normally 3-7 days)
Physiologically what’s happening:
The drop in progesterone triggers the uterus to shed its lining.
Menstrual fluid, which contains blood, the uterine lining, and cervical fluid is released, normally about 30-80 mL over 3-7 days.
How this impacts you:
There are a lot of period symptoms that are common such as cramps, headaches, and GI distress.
However, just because something is common doesn’t mean it’s “normal”. While mild symptoms may be “normal”, severe symptoms may indicate an underlying issue.
Please see your healthcare provider about any symptoms you experience.
Hormones are low during the menstrual phase.
Early research suggests spatial awareness may be increased during the menstrual phase.
Personally, I found learning how my hormone cycle influences me to be extremely empowering. For example, it helps me feel more compassion towards myself when I’m tired during my luteal phase and makes me want to take advantage of my energy during my follicular phase. It’s pretty cool to listen to my body and be able to adapt to what it needs during each phase when possible. Of course everyone is different and if you are interested in how your hormone cycle may be impacting you, I highly recommend tracking your cycle, mood, energy levels, etc. Preferably, I recommend using pen and paper instead of an app for privacy reasons.
As I wrote this post, I found myself wanting to add more and more detail. In an effort to avoid making this post too long, more posts to come on this topic! Are there any menstrual cycle topics you want to learn more about in particular? Have you noticed patterns in how your menstrual cycle makes you feel? Let me know in the comments!
Glossary of Terms (Alphabetical Order):
Corpus Luteum: Formed by the follicle that ruptured during ovulation, releases progesterone, without pregnancy it lasts about 10-14 days
Estrogen, specifically estradiol: Made by ovaries, Increases mood and libido, improves insulin sensitivity, helps with bone, heart, muscle, brain, and skin health; causes uterine lining to thicken to prepare for possible pregnancy; causes you to produce fertile cervical fluid
Follicular Stimulating Hormone (FSH): Made by the pituitary gland, tells ovaries to mature egg follicles
Gonadotropin-releasing hormone (GnRH): made by the hypothalamus, tells the pituitary gland to make FSH and LH
Hypothalamic-pituitary-ovarian axis: a negative feedback loop that regulates the menstrual cycle
Luteinizing Hormone (LH): Made by the pituitary gland, causes ovulation and the formation of the corpus luteum
Progesterone: Made by the corpus luteum, A calming hormone, holds a pregnancy if applicable, counteracts many effects of estrogen; helps prevent present breast cancer; raises your body temp through your thyroid; decreases inflammation, helps prevent heart disease, lowers nervous system activity, helps with sleep and stress
Testosterone: Made by ovaries and adrenal glands, helps with bone and muscle health, libido, mood, and energy, does not vary as drastically throughout the menstrual cycle as estrogen, progesterone, FSH, and LH, may peak around ovulation but otherwise mostly consistent throughout the menstrual cycle
References:
Briden, Lara. (2018). Period repair manual: Natural Treatment for better hormones and better periods. Greenpeak Publishing.
Clancy, Kate. (2023). Period: The real story of menstruation. Princeton University Press.
Hill, Sarah. (2019). This is Your Brain on Birth Control. Penguin Random House.
Ronca, F., Blodgett, J. M., Bruinvels, G., Lowery, M., Raviraj, M., Sandhar, G., Symeonides, N., Jones, C., Loosemore, M., & Burgess, P. W. (2025). Attentional, anticipatory and spatial cognition fluctuate throughout the menstrual cycle: Potential implications for female sport. Neuropsychologia, 206, 108909. https://doi.org/10.1016/j.neuropsychologia.2024.108909
Sims, Stacy. (2016). Roar: How to match your food and fitness to your female physiology for optimum performance, great health, and a strong, lean body for life. Rodale Inc.
Tang, Karen. (2024). It’s Not Hysteria: Everything you need to know about your reproductive health (but were never told). Flatiron Books.
Weschler, Toni. (2015). Taking Charge of Your Fertility: 20th anniversary edition. HarperCollins Publishers.
University of California San Francisco (n.d). Normal menstrual cycle. Center for Reproductive Health. Accessed March 31, 2025. https://crh.ucsf.edu/about-fertility/normal-menstrual-cycle
