Period Hormones

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How do Period Hormones Control The Monthly Flow?

Many people with vaginas and vulvas are unaware that periods ought to be PAINFREE. No belly cramps. No sore boobs. No vulvar irritation. Just 3-4 days of moderate bleeding.

If you didn’t know this, you’re not alone.

To spread the word about pain free periods,
our first step is to understand period hormones

What the heck happens during the monthly flow, from a hormone perspective:

A graph of the various period hormones related to mestruation. Keys are that luteinizing hormone spikes just before ovulation, estrogen and progresterone build after ovulation, then both rapidly fall when the egg is not fertilized, leading to menstruation
A graph of the various period hormones related to mestruation. Keys are that luteinizing hormone spikes just before ovulation, estrogen and progresterone build after ovulation, then both rapidly fall when the egg is not fertilized, leading to menstruation

1. Menstrual Phase: The Bleedy Part

In this phase, old blood and various tissues (that were the lining of the uterus, in preparation for potential implantation of fertilized egg) leave the uterus through the vagina. This takes an average of 5 days, but can be 3-8. During this phase, a gland in your brain produces ‘follicular stimulating hormone’ to tell the ovaries to get busy ripening eggs, or “follicles” the fluid filled sacs that contain the eggs. Your period hormones are getting to work starting your next cycle already!

2. After your period, before Ovulation

A. Your ovaries are in what is called the “Follicular Phase”, where a few eggs start to enlarge and ripen…hoping to become “the one” that gets released! Halfway through this phase, the biggest follicle becomes “dominant” and starts to make more Estrogen. It will be the next egg released.

B. After your period, the uterus builds back up lining in preparation for what it hopes is a fertilized egg to implant at the next cycle. This is called the “Proliferative Phase”.


3. Ovulation (egg is released)

When the dominant follicle has produced enough estrogen, the brain releases luteinizing hormone, which causes ovulation. Ovulation is the release of the biggest egg, the dominant follicle, usually about mid-cycle, or day 14 from one of your ovaries.

Your uterus has it’s plushest cushioning of blood vessels, just waiting to welcome a fertilized egg!


4. After Ovulation, Pre Menstruation

A. Ovaries: Now that the dominant follicle has been released, the ovaries enter “The Luteal Phase.” The ‘hole’ that the dominant follicle was released from, closes off and becomes “corpus luteum”, producing estrogen and progesterone. Progesterone peaks mid-phase here. If the egg is fertilized, this corpus luteum supports the early embryo. If not fertilized, the corpus luteum breaks down, and the drop in estrogen and progesterone causes menstruation.

This image from shutter stock shows the evolution of a dominant follicle from an ovary, and 'the hole' that is left after it is released, becoming the corpus lute, which produces estrogen and progesterone until the egg is fertilized (or not).
Evolution of a dominant follicle, and the fate of ‘the hole’ that the dominant follicle was released from. Because pictures are easier than words, sometimes 🙂

B. Uterus: After ovulation, the Uterus enters the “Secretory Phase.” In this phase, the lining of the uterus produces chemicals that can support a new embryo.  The most notable of these chemicals are prostaglandins, which rise after ovulation and peak during menstruation.  

If no fertilization occurs, the corpus luteum stops producing estrogen and progesterone.  This drop in estrogen and progesterone, along with presence of prostaglandins, cause the uterine blood vessels to constrict, the muscles to contract, and the lining of endometrium begins to break down and menstruation occurs (we bleed again).  And the cycle repeats. 


5. What if the egg is fertilized? What happens to period hormones at that time?

If the egg is fertilized, prostaglandins are inhibited, and the menstrual phase does not occur…and the hormones of pregnancy are a whole additional story.  


Phew, no wonder no one ever explained this to us, right??

But what about Endo? Or the Pill? Or what happens at Menopause?

Endometriosis?  That is different than painful periods, but understanding the hormones is still valuable in your journey.  Post Menopausal?  On the pill?

Those are all loaded questions, worthy of their own posts. Check back soon 🙂

Understanding how different hormone presence (or absence) can be related to symptoms can help you understand what your body is experiencing, and give you tools to lessen symptoms, not just cover them up!  Read on and enjoy!

Period Hormone Imbalance can contribute to negative period symptoms of pain.

Fluctuations and imbalances in these period hormones (due to stress, dietary considerations, physical considerations, etc), is what causes us to have negative period symptoms.

I know it’s a lot, but read this post a few times over, refer to the charts and images, and begin to understand what is ‘normal’ in this period hormone flux. 

If you are having negative symptoms, I recommend gently tracking them, for a couple of months.  You may notice a pattern, ie, ‘my breasts are regularly tender around ovulation, and worse if I am drinking a lot of caffeine.”  Or, “my low back is sore the day before my menstruation begins.”  Additionally “I get irritated bowels and loose stool the first two days of my bleeding cycle.”  All are common, and interesting, and potentially can be helped my balancing stress and hormone levels, as well as taking care of your pelvic floor!  

How did I never know that periods were supposed to be pain-free??

You and me both, friends. This fact literally blew my mind.

POV: It’s 2020. I’ve been a Doctor of Physical Therapy 15+ years and had the first of my Board Certified Specializations for nearly 8 years. I was chatting with my girl, Erin Borbet, acupuncturist to the stars, and guru of all that is hormone-related, about how I’ve always had extremely sore breasts in the week leading up to my period. She was like “oh, that’s common, but not normal.”

I was like… “I say that ALL THE TIME, but about incontnence and pelvic pain. Everybody ‘knows’ you are supposed to be uncomfortable before your period, right?”

She was like: “Doctor, heal thyself!”

Okay, in truth, she didn’t say that…but she basically told me that PMS symptoms are generally due to an imbalance of hormones. And if one becomes dominant, it can lead to sore boobs, or back, or moodiness.

Mind Blown. I had noticed, in my professional practice, that clients would report lessened period cramping after they worked on their pelvic floor muscle spasms, but I never considered having “pain free periods” as a realistic or reasonable goal. These individuals coming to see me had tailbone pain and couldn’t sit on a chair. Or had pelvic pain and couldn’t use a tampon, but wanted to have a baby. They had ‘bigger issues’ to deal with.

In my arrogance, that’s really what I thought. But I think really, it was because I didn’t know there was more to offer them. So, instead of being a part of the problem (or at least complicit in its acceptance as normal), I began to work to change the perception. We started with a fun Instagram LIVE (I am still so new to Insta! It was a hoot!), and I am continuing now with Blog posts, and outreach on other social platforms. It has space in my upcoming Pelvic Floored book!

This blog post goes over how fluctuations in these period hormones can cause many ‘common, but not normal’ period symptoms!

Thanks for reading! If you haven’t already, please follow me on Instagram and join my mailing list to be kept up to date on other AMAZING blog posts with practical tips for improving your pelvic (and overall) health!

If you’re ready to take the next step, via either working with me one on one, or purchasing an online course, I am so proud of you! You deserve this, & I can’t wait to be a part of your success story!!

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Thanks for reading!

xoxo, Dr. Kelly

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Period Hormones
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