Research on Yoga for Menstrual Pain

By Nikhil Ramburn and Sat Bir Singh Khalsa, Ph.D.

Dysmenorrhea is defined as painful menstrual cramps originating from the uterus. The condition is commonly divided into two categories, namely primary dysmenorrhea, which is menstrual pain without an identifiable disease, and secondary dysmenorrhea, which has an identifiable cause such as endometriosis, fibroids, pelvic inflammatory disease, and the use of intrauterine contraceptive devices. The risk factors for dysmenorrhea include the duration of menstrual flow, younger age at onset of menstruation (menarche), smoking, obesity, and alcohol consumption. High levels of stress, depression, and anxiety can also greatly increase the incidence of dysmenorrhea. The disruption of social networks also appears to be a contributing factor to the condition. Although prevalence estimates vary from 45 percent to 95 percent, dysmenorrhea seems to be the most common women’s health condition regardless of age and nationality. Despite this high prevalence, conventional treatment most commonly includes birth control pills and painkillers such as non-steroidal anti-inflammatory drugs (NSAIDs; e.g. ibuprofen, naproxen, etc.). Many women also choose behavioral therapy for pain management such as relaxation and positive imagery although the evidence is limited as to their efficacy.

Yoga may prove to be a valuable complementary behavioral approach that does not carry the same health risks as conventional pharmacotherapy. Indeed, NSAIDs can induce stomach ulcers and birth control pills have been associated with an increased risk of thrombosis. Yoga may be an efficacious alternative since the practice can increase muscular strength and flexibility, thereby relieving congestion in organs, especially the uterus. Yoga can also reduce pain by helping the brain’s pain center regulate the pain mechanisms located in the spinal cord and moderate the secretion of natural painkillers in the body. Since yoga has been associated with enhanced self-regulation and a reduction in sympathetic activation and stress dominance, the practice may help an individual better cope with stress, anxiety, and depression which are risk factors for dysmenorrhea. Slow yogic breathing exercises may also reduce pain since focused exhalation reduces tension and stress. Finally, yoga may help reestablish a balance between the endocrine and reproductive systems.

There is growing research trial evidence supporting the practice of yoga to alleviate menstrual pain. A recent review of the literature included fifteen studies evaluating the impact of yoga on menstrual disorders. Of these, nine were randomized controlled trials (RCTs; the gold standard of scientific study design), and six were single group or single case intervention studies. The majority of the studies were conducted in India and the rest in other Asian countries and Iran (curiously, although researchers in the U.S. have been major contributors to research on yoga, to our knowledge, there is no U.S.-based research on this topic). The studies in this review focused on the impact of yoga on premenstrual symptoms and menstrual distress. Participants ranged between 13 and 45 years and were administered a range of yoga interventions including physical yoga, breathing, meditation, and two studies even measured the sole impact of progressive muscle relaxation techniques called Yoga Nidra. All the studies reported beneficial outcomes such as lower self-reported menstrual distress, lower serum homocysteine (which is an amino acid associated with vascular stress and blood clots), and reduced pain scores. It would be interesting to study the effects of yoga on menstruation in regular yoga practitioners, however, such a study has not yet been done.

A 2011 study conducted in the Department of Midwifery at the Islamic Azad University in Iran found that yoga reduced the severity and duration of primary dysmenorrhea. The trial participants consisted of 92 female students, 18-22 years old who were randomly assigned to the experimental yoga group or a control group. The experimental group practiced cobra, cat, and fish poses (common Hatha Yoga poses) during the luteal phase of the menstrual cycle and each group was evaluated for three menstrual cycles. The researchers found a significant improvement in pain intensity and duration in the yoga group when compared to both the baseline scores and the control group subjects. These preliminary findings suggest that yoga poses may be a safe and effective treatment for primary dysmenorrhea.

A study of 113 medical students from the Dr. Pinnamaneni Siddhartha Institute of Medical Sciences in India also measured the effect of yoga on primary dysmenorrhea. The 60 experimental group participants attended 40 minutes of yoga class every day for three months. In addition, they practiced 10 minutes of pranayama and meditation daily. The researchers observed that students who had the highest menstrual pain scores also scored higher on the stress scale. The results revealed that the yoga intervention group had pronounced and significant improvements in perceived stress and 82 percent of the subjects in this group reported complete stress relief. Furthermore, menstrual pain was significantly reduced after the yoga intervention when compared both to baseline and the control group.

Another recent study which investigated the effects of yoga on menstrual distress in undergraduate students was conducted at the nursing college of Konyang University in South Korea. Forty students were randomized to either the yoga intervention or the control group. The experimental group practiced yoga for 60 minutes weekly for 12 weeks and the program consisted of physical exercise, relaxation, and meditation. Once again, the researchers observed a significant decrease in menstrual pain intensity in yoga participants when compared to the control group.

Finally, a study from the School of Physical Therapy at Khon Kaen University in Thailand examined the effects of a specific set of yoga exercises on menstrual pain. 34 subjects, aged 18-22 years were randomized into either a yoga group or control group. The experimental group practiced yoga for 30 minutes twice a week over a 12-week period. The specific sequence started with a relaxation pose (Shavasana) followed by an active Sun Salutation series (Surya Namaskara) and ended with a series of poses targeting the lower legs and pelvis. The researchers noted significant improvements in menstrual pain, physical fitness, and quality of life in the yoga group when compared to baseline and to the control group.

Despite the growing body of evidence supporting the use of yoga to alleviate dysmenorrhea symptoms, the mechanisms underlying yoga’s efficacy are still not fully understood. One study focusing on Yoga Nidra found that the practice modulated the autonomic nervous system to decrease sympathetic dominance and this was correlated with a decrease in menstrual pain. Another possible mechanism is the reduction in serum homocysteine levels observed after an 8-week yoga intervention in one study. The reduction in this particular amino-acid may point to a restoration of the endothelial function of the uterus. Other research was able to rule out the role of the hormone progesterone in accounting for yoga’s therapeutic benefits. It is known that a progesterone decrease can lead to excessive uterine contraction during menses, however, after a 3-month yoga intervention, no difference was noted in the premenstrual progesterone levels of participants despite positive improvements in self-reported pain relief. However, ground-breaking evidence after yet another Yoga Nidra intervention suggests that yoga may modulate the neuroendocrine system and effectively change the hormonal profile of women with menstrual irregularities by reducing the thyroid-stimulating hormone, follicle-stimulating hormone, luteinizing hormone, and prolactin.

In summary, these encouraging albeit preliminary findings suggest that yoga therapy may be a viable complementary treatment for dysmenorrhea in reducing menstrual cramps and additionally lessening psychosocial stress levels that aggravate dysmenorrhea. Several studies to date have clearly presented their research methods and had replicable aims. However, the variability of yoga interventions across the studies conducted to date limits analysis of the results. Future studies should address the previous limitations of bias, high attrition rates, lack of randomization, lack of long-term follow-up, and self-reported methods to measure outcomes. In addition, by studying a broader segment of the population, the findings may be generalized. Finally, additional trials should further address the mechanisms behind yoga’s effectiveness for dysmenorrhea.

Nikhil Rayburn grew up practicing yoga under mango trees in the tropics. He is a certified Kundalini Yoga teacher and has taught yoga to children and adults in Vermont, New Mexico, Connecticut, India, France, and Mauritius. He is a regular contributor to the Kundalini Research Institute newsletter and explores current yoga research.

Sat Bir Singh Khalsa, Ph.D. is the KRI Director of Research, Research Director for the Kripalu Center for Yoga & Health, and Assistant Professor of Medicine at Harvard Medical School. He has practiced a Kundalini Yoga lifestyle since 1973 and is a KRI certified Kundalini Yoga instructor. He has conducted research on yoga for insomnia, stress, anxiety disorders, and yoga in public schools. He is editor in chief of the International Journal of Yoga Therapy and The Principles and Practice of Yoga in Health Care and author of the Harvard Medical School ebook Your Brain on Yoga.