PMS, Mood Swings, and Inflammation: What’s Really Driving Your Symptoms

Dr. Ivy Moreno in womens health May 19, 2026

Premenstrual symptoms are often dismissed as a normal part of the menstrual cycle.

But for many women, PMS affects mood, energy, sleep, digestion, and overall quality of life in a way that feels anything but normal.

What’s often missing from this conversation is that PMS is not just a hormonal issue.

It’s a whole-body response involving:

the immune system
the nervous system
metabolic health
and hormone signaling pathways¹

Understanding this broader picture is what allows us to move beyond symptom management—and toward true resolution.

PMS Is About Sensitivity, Not Just Hormones

One of the most important (and often overlooked) findings in research is this:

Most women with PMS have normal hormone levels.¹

The difference is how the brain and body respond to those hormonal shifts.

This is referred to as hormone sensitivity.

In other words:
It’s not just what your hormones are doing
It’s how your body is reacting to them

The Inflammation Connection

Inflammation plays a central role in PMS.

Higher levels of inflammatory markers, including C-reactive protein (CRP), have been associated with increased PMS severity.²

Inflammation can influence:

neurotransmitter activity
pain perception
fluid retention
fatigue
mood regulation

This helps explain why PMS symptoms are both physical and emotional.

Toxicity and Endocrine Disruptors

While there are many causes of inflammation, there are a few key considerations that I always bring up with patients who are struggling with their reproductive health. Whether it’s PMS, endometriosis, fibroids, pain with sex, recurrent infections like UTIs and BV, or infertility, we have to remember the role that endocrine disruptors and other toxins play.

Let’s talk about cotton for a moment. Did you know that cotton is considered the world’s “dirtiest” and one of the most chemically intensive crops? It uses an estimated 16%-25% of the world’s insecticides and 6%-10% of pesticides. Some of the substances used to treat cotton are classified as hazardous by the World Health Organization and 7 of the 15 most common pesticides used in US cotton are considered possible, likely, or known carcinogens. Finished products often contain formaldehyde and PFCs (a subset of PFAS, the forever chemicals).

And guess where this “dirty”cotton often shows up?

In your underwear
In your tampons
In your menstrual pads

That means that one of the most toxic materials is snuggled up right next to your most intimate and absorbent body parts.

If we extend the conversation to intimacy products, many personal lubricants and condoms contain chemicals, like Nonoxynol-9 (N-9) that are acutely toxic to the vaginal flora.

Toilet paper often contains harmful substances, most notably PFAS (“forever chemicals”), formaldehyde, and chlorine bleaching by-products. These chemicals are used to enhance softness, strength, or color, but are also linked to cancer, hormone disruption, and skin irritation.³

So it’s really no wonder when patients come to us with hormonal and reproductive concerns that feel especially worse around their periods or with intimacy.

Now let’s be honest, how many of your conventional docs have had this conversation with you? Most of our patients are shocked to learn it.

Hormones, the Brain, and Mood Changes

In the second half of the cycle (luteal phase), progesterone rises.

Progesterone is metabolized into allopregnanolone, a compound that interacts with GABA receptors in the brain—producing calming, anti-anxiety effects.⁴

However, in some women:

This pathway becomes dysregulated
The calming effect is reduced
The brain becomes more reactive

This can lead to:

irritability
anxiety
mood swings
sleep disruption

This mechanism is especially relevant in PMDD (Premenstrual Dysphoric Disorder).⁵

When PMS Becomes PMDD

PMDD is a more severe, clinically recognized form of PMS.

It is characterized by:

intense mood changes
depression
anxiety
irritability
difficulty functioning in daily life

Research suggests PMDD is not caused by abnormal hormone levels—but by an increased sensitivity of the brain to normal hormonal fluctuations, particularly involving neurosteroids like allopregnanolone.⁵

Inflammation and stress can further amplify this sensitivity.

The Role of PMOS (formerly PCOS)

Polyendocrine Metabolic Ovarian Syndrome (PMOS – formerly known as Polycystic Ovary Syndrome or PCOS) is often thought of as a condition of irregular cycles and androgens—but it is also deeply connected to inflammation.

PMOS is associated with:

insulin resistance
elevated inflammatory markers
androgen imbalance⁶

This can contribute to:

mood instability
irregular ovulation
worsened PMS symptoms

Blood sugar dysregulation plays a particularly important role here, as insulin directly influences hormone signaling.

The Role of Endometriosis

Endometriosis is a chronic inflammatory condition in which endometrial-like tissue grows outside the uterus.

It is strongly associated with:

systemic inflammation
estrogen dominance
immune system dysregulation⁷

Symptoms often include:

severe menstrual pain
fatigue
digestive symptoms
mood changes

Because inflammation is a central driver, many individuals with endometriosis also experience heightened PMS symptoms and sensitivity.

The Stress-Inflammation-Hormone Loop

Stress is one of the most significant amplifiers of PMS.

Chronic stress:

increases cortisol
promotes inflammation
disrupts ovulation
lowers progesterone

This creates a feedback loop:
Stress → inflammation → hormone imbalance → worsened PMS → more stress⁸

Breaking this cycle is often a key part of treatment.

Blood Sugar and Mood Stability

Blood sugar instability is one of the most under-recognized contributors to PMS.

Fluctuations in glucose and insulin can lead to:

irritability
anxiety
cravings
energy crashes

Insulin also influences ovarian hormone production and androgen balance, particularly in PMOS.⁶

Stable blood sugar = more stable mood and hormonal signaling.

Gut Health and Estrogen Metabolism

The gut microbiome plays a direct role in estrogen regulation through what is known as the estrobolome.

When gut health is compromised:

estrogen may be reabsorbed instead of eliminated
inflammation may increase
hormone balance may shift⁹

This is why digestive symptoms and PMS often occur together.

A Whole-Body Approach to Supporting PMS

Instead of suppressing symptoms, a functional approach focuses on improving how the body responds to hormonal changes.

This often includes:

Supporting Inflammation Balance

Anti-inflammatory nutrition
Omega-3 fatty acids
Polyphenol-rich foods

Supporting Hormone Metabolism

Liver support (cruciferous vegetables, key nutrients)
Gut health optimization
Regular elimination

Nervous System Regulation

Sleep support
Stress reduction
Gentle movement

Blood Sugar Stability

Protein with meals
Balanced macronutrients
Consistent meal timing

Targeted Herbal and Nutritional Support

Depending on the individual, this may include:

Vitex (chaste tree) for progesterone support
Magnesium for mood and nervous system regulation
B6 for neurotransmitter support
Seed cycling as a gentle food-based approach

(These are individualized and not one-size-fits-all.)

Why Your Symptoms Change Month to Month

One of the most common questions is:

“Why is my PMS worse some months than others?”

The answer lies in variability across:

stress levels
sleep quality
inflammation
nutrition
gut health

Your hormones follow a rhythm.

Your lifestyle and physiology influence how that rhythm is experienced.

Final Thoughts

PMS is not just about hormones.

It’s about how your body responds to them.

And when we address:

inflammation
stress
metabolism
and nervous system regulation

Symptoms often improve in a meaningful and lasting way.

Your body is not working against you.

It’s asking for support.

References

Rapkin AJ, Akopians AL. Premenstrual syndrome and PMDD. Endocrinol Metab Clin North Am. 2012.
Bertone-Johnson ER et al. Inflammation and PMS. J Womens Health. 2014.
Environmental Working Group. (2023, March 1). Study: Toilet paper a major source of toxic “forever chemicals” in wastewater. https://www.ewg.org/news-insights/news-release/2023/03/study-toilet-paper-major-source-toxic-forever-chemicals
Reddy DS. Neurosteroids and mood. Neurobiology of Stress. 2018.
Hantsoo L, Epperson CN. PMDD pathophysiology. Curr Psychiatry Rep. 2015.
Diamanti-Kandarakis E et al. Insulin resistance and PCOS. Endocr Rev. 2012.
Zondervan KT et al. Endometriosis. Nat Rev Dis Primers. 2018.
Chrousos GP. Stress and inflammation. Nat Rev Endocrinol. 2009.
Baker JM et al. Estrobolome and estrogen metabolism. Nat Rev Endocrinol. 2017.
Environmental Justice Foundation. (2007). The deadly chemicals in cotton. Environmental Justice Foundation in collaboration with Pesticide Action Network UK.
The Organic Center. (2024, October 28). The Organic Center unveils the real facts about conventional cotton: Report urges transparency and data sharing.
Organic Trade Association. (2021). Pesticides, fertilizers, and GMOs in conventional cotton fact sheet.
Chakraborty, M., Dayal, A., & Ratna, M. S. (2007). Cotton textile processing: Waste generation and effluent treatment. The Journal of Cotton Science, 11(3), 141–153.
Naik, S. D., & Shailaja, D. N. (2024). Chemical processing of cotton textiles. In Advanced materials and technologies for sustainable textiles (pp. 305–330). Springer, Singapore.
Study.com. (n.d.). Formaldehyde in clothing: Negative effects, limits & testing.