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  • Writer's pictureDr. Emma Lee ND

Painful Periods? Start With the Gut!

Updated: Mar 11, 2023

I wish I could shout this from the rooftops: painful periods are not normal! There is even a medical term for it – dysmenorrhea. Similarly to all other PMS (pre-menstrual syndrome) symptoms, period-related abdominal pain and cramping is usually a sign of an underlying hormonal imbalance. This is known as primary dysmenorrhea, where there is no identifiable disease or physical abnormality contributing to the menstrual pain. It is of course important to first seek medical advice in order to rule out the possibility of secondary dysmenorrhea, where the presence of a medical condition, such as PCOS, endometriosis, or other possible reproductive or gastro-intestinal disorder, is at the root of the pain.

Primary Dysmenorrhea

Most menstruating individuals have been told that period pain is to be expected and there’s not much that can be done. Painkillers are often presented as the solution, but they only temporarily mask the symptom. The underlying issue – ongoing inflammation – is never addressed.

During the first half of the menstrual cycle, or the follicular phase, rising estrogen levels trigger the production of inflammatory prostaglandins, specifically PgF2-α and PgE2. These hormone-like compounds play the crucial role of promoting uterine contractions near the end of the luteal phase, the second half of your menstrual cycle, that are necessary for the shedding of the uterine lining when a pregnancy has not occurred. This is all part of a normal menstrual cycle. However, research has found that women with primary dysmenorrhea have significantly higher estrogen levels, up to 8 – 13x higher than those who do not report menstrual pain. More estrogen leads to more prostaglandins, and therefore more intense uterine contractions. As the uterus is a muscle, prolonged contractions means less oxygen is being delivered to the tissue and more pain.

How Gut Health Ties In

The presence of any inflammation elsewhere in the body will have a compounding effect on the increased uterine contractions present in primary dysmenorrhea, and the gut is usually the biggest culprit. There is a myriad of stressors that adversely affect gut health – exposure to pesticides and herbicides in our produce, poor diet, antibiotics use, infections, and chronic stress are but a few – and they can all cause damage to our microbiome and gut lining , which over time leads to systemic inflammation. Additionally, excess hormones are metabolized by the liver and eliminated through the digestive tract, so if the system is not functioning optimally, hormones meant for excretion can be re-absorbed and put back into circulation.

Some signs and symptoms that your gut is not functioning optimally include, but are not limited to, a tendency toward constipation or diarrhea, indigestion, excessive gas, bloating or cramping, and heartburn. If you’re experiencing any of the above, it may be worth exploring the following interventions and supplements.

Diet and Lifestyle

One of the main determinants of gut health is diet. Aiming for a diet that is composed primarily of whole foods, is vegetable-dominant, and includes lots of fats from nuts, fish, and eggs, will help you consume more anti-oxidants and other anti-inflammatory nutrients. Pay attention to the sources of your food as well. For example, the omega profiles in animal products can differ depending on how they were raised. Farmed fish and conventional caged eggs contain a lower omega-3 to omega-6 ratio than wild-caught fish and free-range eggs. By choosing organic where possible, you will also help to limit your exposure to toxins like glyphosate, which disrupt the microbiome,.

In terms of physical movement, consistency is more important than the type of exercise when it comes gut health. Regular endurance exercise and resistance training both improve the microbial make-up in the digestive tract. As little as 20 minutes of moderate-intensity aerobic training 3x/week can lead to an increase in bacterial diversity after 8 weeks. Exercise also helps to reduce transit time in the large intestine, which would benefit the excretion of excess hormones, as mentioned previously.


There is increasing research around the impact of the gut microbiome on digestive and immune health, with an ever growing understanding on how certain bacterial species and strains activate anti-inflammatory pathways while others promote a “leaky gut” and systemic inflammation. Supplementing with probiotics is an easy first step to re-establish a healthy gut, but not all probiotics are created equal and there are a few criteria that you should look for when choosing a supplement –

Human Strains

This is first and foremost the most important factor when it comes to efficacy. Human-sourced bacteria have been shown to colonize the digestive tract, whereas dairy or soil sourced strains are much more transient, do not adhere very well, and easily get washed out from our gut.

Clinically Researched Strains

Look for a company that performs clinical studies on the specific bacterial strains included in their supplements. Bacterial species (names listed in italics) refer to a broad category that often includes numerous strains (usually specified as letters and numbers in parenthesis following the species name) with differing characteristics. Just because two strains both belong to the same species does not mean that they have the similar strengths or the ability to confer the same benefits!

Prebiotic Content

Some probiotics also contain prebiotics, such as FOS (fructo-oligosaccharides), which are intended as food for your gut bacteria. However, prebiotics indiscriminately feed both beneficial and pathogenic bacterial populations and can therefore aggravate symptoms of dysbiosis such as bloating, constipation, and diarrhea. So unless you’re certain that you do not currently have an overgrowth of bad bacteria, it is best to avoid prebiotic-containing supplements initially.

CFU Count

Lastly, CFU refers to colony-forming units, or the concentration of bacteria per serving. A higher CFU count, such as 25 billion CFU or higher, would be desirable if you’re starting off with lots of digestive symptoms, but isn’t necessary if you’re looking for more of a maintenance dose.


In addition to the beneficial bacteria themselves, their metabolites also contribute to gut health. One of the key microbial products are short-chain fatty acids (SCFAs), including butyric acid or butyrate, which provides many crucial functions. Butyrate is the main source of fuel for our colonocytes, the cells lining our colon, and helps to maintain the integrity of our digestive tract, minimizing the likelihood of harmful molecules escaping into systemic circulation and triggering the inflammatory cascade. Butyrate also acts as a direct regulator of our immune system and has been shown to exhibit favourable effects on inflammatory conditions such as diabetes, inflammatory bowel diseases, and neurological disorders. Butyrate is usually made by certain gut microbes through the fermentation of dietary fibre, but can also be obtained through supplementation.

Omega 3s

Omega-3 fatty acids are nature’s powerhouse when it comes to combatting inflammation. Getting enough of these healthy fats through diet alone can be challenging, so choosing a clean supplement – one that is sustainably sourced and free of heavy metals – will help you meet your daily requirements. Research has shown that adding in as little as 300 mg of omega-3s (180 mg of EPA and 120 mg of DHA) per day can lead to a significant reduction in the severity of primary dysmenorrhea and decrease the need for over-the-counter pain medications.

Additional Investigations

In certain cases, where primary dysmenorrhea persist, further testing may be beneficial. Sometimes inflammation arising from the gut can be traced to food sensitivities or specific overgrowth of certain pathogenic bacteria, so testing like food sensitivity panels and stool analysis can provide insight and help direct more targeted solutions. Detailed hormonal tests can be useful if you are also experiencing irregularities in your menstrual cycle. A naturopathic doctor can help you get to the root cause of what’s going on and offer you an individualized treatment plan that encompasses nutritional and lifestyle suggestions, as well as orthomolecular and botanical supports, and any other additional higher level interventions if they are needed.


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