Dysmenorrhea: Omega 3s are effective against menstrual pain

Doctors call it "dysmenorrhea," and women experience it every month as menstrual pain sometimes so severe as to be disabling. For those who are looking for a solution, Omega 3 supplements could be a viable and safe option, especially if fish does not find much room in their diet.

Omega 3 supplements could help reduce menstrual pain, allowing women who have to take painkillers to combat dysmenorrhea to reduce or even abandon the use of medication.

Suggesting this is an analysis of data available in the scientific literature published in the journal Nutrition & Dietetics by a group of experts from Deakin University (Victoria, Australia) led by dietitian Rhiannon Snipe, who suggest that women who start out with low baseline levels of Omega 3, for example, because they do not eat enough fish, may benefit most.

Menstrual pain: symptoms and consequences

Menstrual pain is a widespread problem that can also be associated with conditions such as endometriosis, fibroids, or pelvic inflammatory disease. The discomfort may be felt in the lower abdomen, but may also extend to the back and thighs; there is also no shortage of possible systemic complaints, such as headache, dizziness, insomnia, nausea, vomiting, and diarrhea.

When particularly strong, these symptoms can interfere with good rest and mood. They sometimes make it impossible to carry out normal daily activities, attend school or go to work, significantly reducing the quality of life of women who suffer from them.

The causes of menstrual pain

Different causes may lie behind the symptoms of dysmenorrhea (a medical term used to refer to menstrual pain). Some point the finger at anatomical abnormalities, such as the shape or length of the cervix; others point out that risk factors include young age, smoking, too much or too little weight, and menstrual cycles that are longer than normal.

In this picture, inflammation seems to play a particularly significant role. In fact, dysmenorrhea would depend on an excess production of prostaglandins, inflammatory molecules that are more abundant in the menstrual blood of women with dysmenorrhea.

Prostaglandins would stimulate smooth muscle contraction and narrowing (vasoconstriction) of blood vessels associated with the endometrium (the tissue that lines the uterus internally). This phenomenon would reduce the supply of oxygen to the endometrium, cause pain, and increase the levels of other prostaglandins involved in the inflammatory phenomena associated with menstruation.

The fact that nonsteroidal anti-inflammatory drugs (NSAIDs) and acetaminophen, which precisely reduce prostaglandin synthesis, are effective against menstrual pain supports the hypothesis that these molecules play a key role in the occurrence of dysmenorrhea.  

How to combat menstrual pain

Many women keep the problem at bay thanks to hormonal contraceptives, which effectively eliminate the root of the phenomenon that leads to the onset of pain: the menstrual cycle. Others include those who try to control the pain with hot packs, rests and the aforementioned medications. NSAIDs succeed in relieving it in a great many cases, but they can be associated with side effects (such as digestive problems) and contraindications (such as gastric ulcer).

Acting on nutrition could be a particularly suitable strategy for all those who cannot rely on drugs due to adverse effects or contraindications of this kind or who, more simply, prefer solutions perceived as more natural. In fact, what we eat also influences the inflammatory state of our body, and if dysmenorrhea has inflammation among its causes, a diet rich in anti-inflammatory molecules could help combat it.

Unfortunately, many modern diets are full of fats with pro-inflammatory properties. These are not only trans fats (which we should steer clear of as much as possible) or saturated fats (which, partly for other reasons, should never exceed 10 percent of daily energy intake from food) but also some polyunsaturated fats: the 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 prostaglandins believed to be associated with menstrual pain are also produced. Other polyunsaturated fats, on the other hand, lead to reduced levels of arachidonic acid and its derivatives involved in the onset of dysmenorrhea; it is precisely the Omega 3s on which Deakin University experts focused their analysis.

Omega 3 against menstrual pain: evidence for effectiveness

Snipe and colleagues scoured the scientific literature for all studies conducted on women and published in English up to Jan. 1, 2023, in which Omega 3 intake with food or dietary supplements and menstrual pain or prostaglandin levels had been considered. From the selection made, 12 publications emerged; all had included comparisons between a group of women who had taken Omega 3 supplements and a group of women who had taken either a placebo or a control group.

Ten of the 12 studies found that taking long-chain Omega 3 supplements reduced the severity of dysmenorrhea. The reported 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 to 3 months. The reduction in intensity of menstrual pain observed ranged from 22 to 66 percent.

One of the remaining two studies also reports a significant reduction in pain (as much as 62 percent). However, its authors did not perform the statistical analysis necessary to assess the significance of the benefits found.

Finally, in 6 of the 7 studies in which participants had also taken painkillers, Omega 3 supplementation was associated with less use of these drugs.

The mechanism of action of Omega 3

The mechanism of action of Omega 3 proposed to explain their benefits against pain associated with menstruation is based precisely on their anti-inflammatory properties. Nevertheless, explain the authors of this analysis, "no study has measured and reported prostaglandin levels."

"Both ibuprofen (...) and paracetamol (...) reduce inflammatory prostaglandin F2α in the menstrual blood of women with dysmenorrhea. Increasing intake of long-chain Omega 3, especially in women who do not get enough and have inadequate basal levels, is thought to exert similar effects through replacing arachidonic acid in cell membranes with EPA and DHA. This would increase the production of anti-inflammatory series 3 prostaglandins and reduce inflammatory series 2 prostaglandins (such as F2α), which cause vasoconstriction (...) and pain in women with dysmenorrhea."

Only further studies can verify this hypothesis. However, "the fact that reduction in analgesic use and significant reduction in dysmenorrhea pain are simultaneously observed after supplementation with long-chain Omega 3 highlights the potential pain-relieving effects of these supplements."

Possible help without serious side effects

The hypothesis that Omega 3 may be useful against menstrual pain also finds support in research that has associated fish consumption (a source of these fatty acids) with reduced prevalence of dysmenorrhea. Taking these clues into account as well, the authors of this analysis suggest that "supplementation of about 300 mg per day of long-chain Omega 3 (...) would seem to be an appropriate starting point for women with dysmenorrhea who eat little fish." 

The authors point out, therefore, that those who would benefit most from increasing their dietary intake of EPA and DHA or taking supplements might be women who, at baseline, consume low amounts of Omega 3. But that's not all. "Other factors, such as wine consumption, smoking, and the form [in which Omega 3s are taken (...) are known to influence levels of long-chain Omega 3s" and, therefore, "are factors that should be considered in research that will be conducted in the future." 

Finally, Snipe and colleagues also explain that "few studies have detected and reported minor side effects," adding that this suggests that "Omega 3 supplements were, in general, well tolerated." According to the researchers, the evidence suggests that "long-chain Omega 3 supplements could reduce dependence on painkillers to manage pain associated with dysmenorrhea or could be effective pain relievers when used in combination with them."

Bibliographic 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/