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Endometriosis Pain Can Be Managed by Targeting the Endocannabinoid System, Says Study

A new study investigates the link between the endocannabinoid system and pain management for endometriosis patients.

Evidence suggests that modulating the body’s endocannabinoid system (ECS) could assist in managing pain caused by endometriosis, according to a new research review. The study, headed by Jerome Bouaziz at the Department of Obstetrics and Gynecology at The Chaim Sheba Medical Center in Israel, investigates the type of pain caused by endometriosis and the endocannabinoid system’s potential role. It was published this month in the journal, Cannabis and Cannabinoid Research.

Known for at times causing severe pain, endometriosis is a condition in which the endometrium — tissue that normally lines the inside of a woman’s uterus — abnormally grows outside of the uterus instead. Areas of endometrial tissue found outside the uterus are called endometrial implants, or lesions. Endometriosis affects an estimated 2 to 10 percent of American women of childbearing age, according to John Hopkins Medicine.

The pain associated with endometriosis is complex, according to Bouaziz, and involves three separate categories: nociceptive, inflammatory, and neuropathic pain. Nociceptive pain develops when sensory receptors of the peripheral nervous system, called nociceptors, are activated. Inflammatory pain, which goes hand-in-hand with nociceptive pain, is initiated by tissue injury that sets off an array of biochemical reactions that produce hypersensitivity to pain. Neuropathic pain arises following damage to the neurons themselves. All three categories of pain are present in endometriosis, making it a challenging condition to manage.

Studies indicate that the endocannabinoid system plays a key role in the establishment of endometriosis and the pain associated with the condition. The endocannabinoid system, made up of cannabinoid receptors CB1 and CB2, endocannabinoids and enzymes, is responsible for regulating many physiological processes, including pain sensation, mood, memory, appetite, sleep, and immune response.

According to Bouaziz’s review, researchers have found the levels and symptoms of endometriosis-associated pain to be linked to a decreased expression of CB1 receptors and a significant increase of endocannabinoids in the plasma. This “suggests a negative feedback loop regulation, which may impair the capability of these mediators to control pain.”

Some of the studies included in the review describe endometriosis as a condition caused by endocannabinoid deficiency. Endocannabinoid deficiency, in which the body doesn’t produce enough endocannabinoids or cannabinoid receptors, has already been linked to several subjective pain syndromes. Women experiencing endometriosis have been found to have lower levels of CB1 receptors in their endometrial tissue, and reduced ECS function has been linked to the growth of endometriosis tissue and a more severe pain experience.

The findings suggest that manipulating the endocannabinoid system could be effective for managing endometriosis-associated pain. The study found evidence that cannabinoid receptor agonists, including the phytocannabinoids found in cannabis, are effective at regulating the inflammatory response, reducing the growth of endometriotic lesions, and controlling neuropathic pain.

“Targeting endocannabinoid modulation to treat pain is probably more than just treating the pain as it may impact several levels of the pathogenesis and the proliferation of the disease. Special attention and further investigation are needed to evaluate the impact of the potential therapeutic side effects, especially on fertility and pregnancy outcomes,” the study concludes.

You can access the entire study, “The Clinical Significance of endocannabinoids in Endometriosis Pain Management,” via Cannabis and Cannabinoid Research.

Learn more about the studies investigating cannabinoids and their effects on endometriosis and menstrual pain by visiting our education page.