Dysmenorrhea: Omega 3 are effective against menstrual pain

Doctors call it “dysmenorrhea”; women experience it every month as menstrual pain, sometimes so intense it becomes disabling. For those seeking a solution, Omega 3 supplements could be a valid and safe option, especially if fish is not a regular part of their diet.

Omega 3 supplements may help reduce menstrual pain, allowing women who take painkillers to combat dysmenorrhea to reduce or even eliminate the need for medication.

This is suggested by an analysis of data available in the scientific literature published in the journal Nutrition & Dietetics by a team of experts from Deakin University (Victoria, Australia) led by dietitian Rhiannon Snipe, according to whom the greatest benefits may be seen in women who start with low baseline levels of Omega 3, for example because they don’t eat enough fish.

Menstrual pain: symptoms and consequences

Menstrual pain is a very common issue and may also be associated with conditions such as endometriosis, fibroids, or pelvic inflammatory disease. The discomfort can be felt in the lower abdomen but may also radiate to the back and thighs; there can also be systemic symptoms like headaches, dizziness, insomnia, nausea, vomiting, and diarrhea.

When especially severe, these symptoms can interfere with restful sleep and mood. Sometimes, they make it impossible to carry out normal daily activities, attend school, or go to work, significantly reducing the quality of life of the women who suffer from them.

The causes of menstrual pain

The symptoms of dysmenorrhea (the medical term for menstrual pain) may be due to various causes. Some blame anatomical anomalies such as the shape or length of the cervix; others note that risk factors include young age, smoking, excessive or insufficient weight, and longer-than-average menstrual cycles.

In this context, inflammation appears to play a particularly significant role. Dysmenorrhea is thought to result from excess production of prostaglandins, inflammatory molecules more abundant in the menstrual blood of women with dysmenorrhea.

Prostaglandins stimulate the contraction of smooth muscles and the constriction (vasoconstriction) of blood vessels associated with the endometrium (the inner lining of the uterus). This phenomenon reduces the oxygen supply to the endometrium, causes pain, and increases levels of other prostaglandins involved in the inflammatory events related to menstruation.

The fact that non-steroidal anti-inflammatory drugs (NSAIDs) and paracetamol — which reduce prostaglandin synthesis — are effective against menstrual pain supports the hypothesis that these molecules play a fundamental role in the onset of dysmenorrhea. 

How to fight menstrual pain

Many women avoid the problem thanks to hormonal contraceptives that essentially eliminate the cycle causing the pain. Others try to manage the pain with warm compresses, rest, and the aforementioned medications. NSAIDs alleviate it in many cases, but may be associated with side effects (like digestive issues) and contraindications (like gastric ulcers).

Adjusting the diet could be a particularly suitable strategy for those who cannot rely on medication due to side effects or contraindications, or who simply prefer more “natural” solutions. What we eat also affects our body’s inflammatory state, and if inflammation is among the causes of dysmenorrhea, a diet rich in anti-inflammatory molecules may help combat it.

Unfortunately, many modern diets are rich in fats with pro-inflammatory properties. These include not just trans fats (which we should avoid as much as possible) or saturated fats (which for various reasons should not exceed 10% of daily caloric intake), but also some polyunsaturated fats: Omega 6s, abundant in many seeds and vegetable oils.

Omega 6s are precursors of arachidonic acid, a molecule closely linked to inflammatory processes and from which the prostaglandins believed to be associated with menstrual pain are produced. Other polyunsaturated fats, instead, reduce levels of arachidonic acid and its derivatives involved in the onset of dysmenorrhea; these are precisely Omega 3s, the focus of the Deakin University experts' analysis.

Omega 3 against menstrual pain: evidence of effectiveness

Snipe and colleagues examined the scientific literature for all studies conducted on women and published in English up to January 1, 2023, that considered Omega 3 intake through food or supplements in relation to menstrual pain or prostaglandin levels. Twelve publications were selected; all compared a group of women taking Omega 3 supplements to a placebo group or control group.

Ten out of the twelve studies found that taking long-chain Omega 3 supplements reduced the severity of dysmenorrhea. Treatments involved taking between 300 mg and 1,800 mg of a combination of the biologically active long-chain Omega 3s (EPA – eicosapentaenoic acid – and DHA – docosahexaenoic acid) for a period of 2–3 months. The reduction in menstrual pain intensity ranged from 22% to 66%.

One of the remaining two studies also reported a notable reduction in pain (as much as 62%). However, its authors did not conduct the statistical analysis necessary to assess the significance of the observed benefits.

Finally, in six out of seven studies where participants also took painkillers, Omega 3 supplementation was associated with reduced use of those drugs.

The mechanism of action of Omega 3s

The proposed mechanism of action of Omega 3s to explain their benefits against menstrual pain is based precisely on their anti-inflammatory properties. Nonetheless, the authors of the analysis explain, “no study measured and reported prostaglandin levels.”

“Both ibuprofen (…) and paracetamol (…) reduce inflammatory prostaglandin F2α in the menstrual blood of women with dysmenorrhea. It is believed that increasing the intake of long-chain Omega 3s, especially in women who don’t get enough and have inadequate baseline levels, exerts similar effects by replacing arachidonic acid in cell membranes with EPA and DHA. This would increase the production of anti-inflammatory series 3 prostaglandins and reduce the inflammatory series 2 ones (like F2α) that cause vasoconstriction (…) and pain in women with dysmenorrhea.”

Only further studies can confirm this hypothesis. However, “the fact that Omega 3 supplementation is associated with both a reduction in the use of analgesics and a significant decrease in dysmenorrhea pain highlights the potential pain-relieving effects of these supplements.”

A possible aid without serious side effects

The hypothesis that Omega 3s may be useful against menstrual pain is also supported by research linking fish consumption (a source of these fatty acids) to reduced prevalence of dysmenorrhea. Considering this evidence, the authors of the analysis suggest that “supplementation of around 300 mg per day of long-chain Omega 3s (…) would seem an adequate starting point for women with dysmenorrhea who eat little fish.” 

The authors therefore emphasize that women who consume low amounts of Omega 3s at baseline may benefit most from increased dietary intake of EPA and DHA or from taking supplements. But not only that. “Other factors are known to influence long-chain Omega 3 levels, such as wine consumption, smoking, and the form in which Omega 3s are taken (…) and therefore should be considered in future research.” 

Finally, Snipe and colleagues also explain that “few studies detected and reported minor side effects,” adding that this suggests that “Omega 3 supplements were generally well tolerated.” According to the researchers, the available data suggest that “long-chain Omega 3 supplements could reduce reliance on painkillers to manage dysmenorrhea-related pain or could be effective painkillers when used in combination with them.”

References:

Snipe RMJ, Brelis B, Kappas C, Young JK, Eishold L, Chui JM, Vatvani MD, Nigro GMD, Hamilton DL, Convit L, Carr A, Condo D. Omega-3 long chain polyunsaturated fatty acids as a potential treatment for reducing dysmenorrhoea pain: Systematic literature review and meta-analysis. Nutr Diet. 2024 Feb;81(1):94-106. doi: 10.1111/1747-0080.12835

Nagy H, Carlson K, Khan MAB. Dysmenorrhea. [Updated 2023 Nov 12]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK560834/