The Endocannabinoid System in Endometriosis-Associated Pain: Mechanisms, Molecular Targets, and Therapeutic Implications

A new 2026 review published in Reproductive Sciences examines the endocannabinoid system (ECS) as a therapeutic target for endometriosis-associated pain, a condition that can cause severe pelvic pain, painful menstruation, painful intercourse, and other chronic symptoms. The authors highlight the ECS because of its established roles in regulating pain, inflammation, and immune activity.

The review found that cannabinoids may influence three major mechanisms involved in endometriosis-associated pain: inflammation, pain signaling and sensitization, and the growth of endometriotic lesions. Cannabinoids interact with both cannabinoid and non-cannabinoid receptors found in endometriotic tissue, while also reducing inflammatory signaling from immune cells such as mast cells and macrophages.

The researchers conclude that the endocannabinoid system is a promising therapeutic target for endometriosis-associated pain, with cannabinoid therapies showing potential to regulate nociception, inflammation, and lesion proliferation. They call for clinical trials to further evaluate cannabinoid-based treatments for people living with endometriosis.

“Endometriosis is a chronic gynecological disorder affecting approximately 10% of reproductive-age women, characterized by the ectopic growth of endometrial tissue and severe pain, including dysmenorrhea, chronic pelvic pain, dyspareunia, dysuria, and dyschezia. Current treatments are limited in efficacy and associated with significant side effects, underscoring the urgent need for novel therapeutic strategies.

The endocannabinoid system (ECS) has emerged as a promising therapeutic target, given its well-established roles in pain modulation, inflammation, and immune regulation. Epidemiological evidence demonstrates that women with endometriosis increasingly use cannabis for symptom self-management, yet the underlying mechanisms remain poorly characterized.

This review integrates preclinical and human evidence to comprehensively evaluate the mechanistic basis of cannabinoid efficacy in endometriosis-associated pain. Evidence from in vitro studies and animal models indicates that cannabinoids target three main mechanisms of endometriosis-associated pain, including inflammation, nociceptive signaling, and lesion proliferation.

Cannabinoids suppress pain signaling and sensitization by interacting with cannabinoid and non-cannabinoid receptors expressed in endometriotic lesions. Cannabinoids attenuate endometriosis-induced inflammation by inhibiting proinflammatory cytokine signaling and reducing the release of inflammatory mediators by mast cells and peritoneal macrophages. Cannabinoids also exert antiproliferative effects in endometriosis models, thereby suppressing the growth of endometriotic lesions.

In conclusion, the ECS is a promising therapeutic target for endometriosis-associated pain, as it regulates nociception, inflammation, and proliferation. These promising findings highlight the potential therapeutic benefits of cannabinoids for endometriosis-associated pain, warranting the need for clinical trials to evaluate the safety and effectiveness of cannabinoid therapies in endometriosis.”

https://pubmed.ncbi.nlm.nih.gov/42745018

https://link.springer.com/article/10.1007/s43032-026-02201-9

Visualization of Endocannabinoids in the Cell.

“A still unsolved, although critical, issue in endocannabinoid research is the mechanism by which the lipophilic compound anandamide (AEA) moves from its site of synthesis, crosses the aqueous milieu, and reaches the different intracellular compartments, where its metabolic and signaling pathways take place. The difficulty of studying intracellular AEA transport and distribution results from the lack of specific probes and techniques to track and visualize this bioactive lipid within the cell. Here, we describe the use of a biotinylated, non-hydrolyzable derivative of AEA (biotin-AEA, b-AEA) for visualizing the subcellular distribution of this endocannabinoid by means of confocal fluorescence microscopy.”

http://www.ncbi.nlm.nih.gov/pubmed/27245913

Anandamide mediates cognitive judgement bias in rats.

“In the present study, we investigated the effects of acute pharmacological manipulation of the endocannabinoid (EC) system on the valence of cognitive judgement bias of rats in the ambiguous-cue interpretation (ACI) paradigm.

Our findings suggest involvement of the endocannabinoid system in the mediation of optimistic judgement bias.”

http://www.ncbi.nlm.nih.gov/pubmed/26363193

Anandamide-evoked activation of vanilloid receptor 1 contributes to the development of bladder hyperreflexia and nociceptive transmission to spinal dorsal horn neurons in cystitis.

  Figure 4.

“The role of anandamide in the development of inflammatory hyperalgesia and visceral hyperreflexia was studied in the rat urinary bladder…

These results suggest that anandamide, through activating TRPV1, contributes to the development of hyperreflexia and hyperalgesia during cystitis.”

http://www.jneurosci.org/content/24/50/11253.long

[The modulatory role of endocannabinoids in sleep].

“The endogenous cannabinoid, or endocannabinoid, system is present in the central nervous system (CNS) of rodents and humans. This system includes receptors, endogenous ligands and enzymes. The presence of cannabinoid receptors, called CB1, in the CNS has been reported in the cerebral cortex, the hippocampus, the cerebellum and the brain stem. This neuroanatomical location suggests that this receptor could modify several physiological functions, such as the consolidation of memory, motor control and the generation of sleep.

 

Recent reports have described the presence of lipids in the CNS that bind to the CB1 receptor. Administration of said molecules induces cannabimimetic effects, and hence it has been suggested that these lipids are endogenous cannabinoids or endocannabinoids. Anandamide, 2-arachidonylglycerol, virodhamine, noladin ether and N-arachidonyldopamine are molecules that belong to the endocannabinoid family. Anandamide has received more attention from researchers because it was the first endocannabinoid to be reported. Pharmacological experiments have shown that this endocannabinoid induces several different intracellular and behavioural changes.

CONCLUSIONS:

In this study, we review the most important pharmacological aspects of exogenous cannabinoids and the neurobiological role played by the endocannabinoid system, including endogenous and exogenous ligands and receptors. We also examine their pharmacological effects on different behaviours, with particular attention given to the modulation of sleep.”

http://www.ncbi.nlm.nih.gov/pubmed/18297624