Endometriosis

What it is

Endometriosis is a chronic estrogen-dependent inflammatory disease in which tissue histologically and functionally similar to the endometrium grows outside the uterus. Common implant sites include the pelvic peritoneum, ovaries (where they form endometriomas), uterosacral ligaments, rectovaginal septum, bladder, bowel, and (less commonly) thoracic and extra-pelvic sites. The implants respond to cyclical hormonal stimulation, producing local inflammation, fibrosis, adhesion formation, and pain.

Prevalence is estimated at 10% of women of reproductive age — roughly 6.5 million patients in the United States and 190 million globally. Diagnosis is often delayed by 7-10 years from symptom onset, in part because pelvic pain has historically been undertreated and in part because definitive diagnosis traditionally requires laparoscopy (with histopathologic confirmation). The 2022 ESHRE Guideline on Endometriosis emphasizes clinical and imaging-based diagnosis over laparoscopic confirmation as the standard of care.

Clinical features include:

• Dysmenorrhea (painful menstruation): typically severe, progressive, and refractory to standard NSAIDs.
• Chronic pelvic pain: non-cyclical pain that may persist throughout the cycle as the disease progresses.
• Dyspareunia (pain with intercourse): particularly deep dyspareunia from rectovaginal or uterosacral lesions.
• Dyschezia and dysuria: pain with bowel movements or urination, particularly cyclical.
• Infertility: present in 30-50% of patients with endometriosis; mechanisms include distorted pelvic anatomy, ovarian reserve compromise, and inflammatory effects on gametes and embryo.
• Fatigue and quality-of-life impairment: consistently reported and underrecognized.

Cannabis and cannabis-derived therapies

Evidence for cannabis in endometriosis is limited. The 2017 NASEM consensus report did not identify endometriosis as a condition with substantial or conclusive evidence; the 2024 update did not change this. No major randomized controlled trial of plant cannabis or pharmaceutical cannabinoids has been completed in an endometriosis population.

Indirect evidence is more substantial. NASEM rated chronic pain in adults at the highest evidence tier (substantial/conclusive). Endometriosis pain has documented neuropathic and centralized components that overlap mechanistically with the chronic-pain syndromes where cannabis has stronger trial evidence.

Observational evidence has been consistently positive:

• Armour et al. (2017, Australian patient survey): ~213 patients, 13% reported cannabis use; ~80% rated it among their most effective pain self-management strategies.
• Sinclair et al. (2020, Australian Endometriosis Survey): cannabis was the highest-rated self-management strategy for pain, sleep, and overall well-being.
• Several US clinic surveys (post-2018): cannabis use is widespread in endometriosis patient populations, with consistent patient-reported pain and quality-of-life benefit.

These observational data show patient demand and consistent self-reported benefit; they do not establish efficacy in the way a randomized trial would. The endometriosis cannabis-trial literature is a major active research gap.

Symptom-specific picture

• Cyclical dysmenorrhea: patient-reported benefit is consistent; mechanism likely involves anti-inflammatory and central-nervous-system pain modulation.
• Chronic pelvic pain (non-cyclical): indirect support from the NASEM chronic-pain evidence base. Centralized chronic pelvic pain has features that overlap with fibromyalgia and other centralized pain syndromes where cannabinoid benefit has been reported.
• Dyspareunia: limited specific evidence; some patients use cannabis topically or inhaled prior to intercourse for symptom management.
• Dyschezia and bladder symptoms: limited specific evidence; chronic-pain-equivalent.
• Lesion size and disease progression: no controlled trial evidence that cannabis reduces endometriotic implant burden, fibrosis, or surgical recurrence.
• Fertility: cannabis use is contraindicated in patients pursuing pregnancy.

Endocannabinoid pharmacology in endometriosis

The endocannabinoid system is expressed throughout the female reproductive tract. CB1 and CB2 receptors are present in endometrium, myometrium, ovary, and fallopian tube. Endometriotic implants show altered CB1 receptor expression compared with healthy endometrium — typically lower CB1 expression in implants, which has motivated mechanistic interest in cannabinoid pharmacotherapy.

In animal models of endometriosis (rodent surgical implant models), CB1 and CB2 agonists have reduced implant growth and pain behaviors in some studies. These preclinical findings have not yet translated to controlled human trials in endometriosis patients.

Estrogen and the endocannabinoid system interact: estrogen modulates FAAH (fatty acid amide hydrolase, which degrades anandamide), and endocannabinoid tone fluctuates across the menstrual cycle. This may contribute to the cyclical pain pattern of endometriosis and is a plausible mechanism by which cannabinoid pharmacotherapy could affect symptom severity.

Standard endometriosis therapy

Cannabis is symptomatic only and does not replace evidence-based hormonal suppression or surgical management:

• NSAIDs (ibuprofen, naproxen, mefenamic acid): first-line for dysmenorrhea.
• Combined oral contraceptives: continuous or cyclical regimens.
• Progestin-only therapies: oral dienogest (FDA-approved for endometriosis in many countries, available in the US under specific access pathways), norethindrone acetate, levonorgestrel IUD.
• GnRH agonists: leuprolide depot, often with hormonal add-back to mitigate bone-mineral-density loss.
• GnRH antagonists: elagolix (FDA-approved 2018 for endometriosis pain), relugolix combination therapy.
• Surgical excision: laparoscopic excision or ablation of endometriotic implants. Excision (especially deep infiltrating endometriosis excision) has the strongest long-term symptom benefit.
• Multimodal pain management: pelvic floor physical therapy, mental health support, and pain psychology.

A patient who substitutes cannabis for hormonal suppression or appropriate surgery may experience progression of lesions and irreversible anatomic damage (especially in deep infiltrating disease or endometriomas affecting ovarian reserve). Cannabis should be coordinated with the gynecologist managing the patient's care.

Drug interactions

• NSAIDs: additive GI effects, particularly in high-dose chronic combined use.
• Combined oral contraceptives and progestins: CBD CYP3A4 inhibition may affect contraceptive steroid metabolism; clinical significance is not well established. Patients relying on hormonal contraception for both endometriosis management and pregnancy prevention should discuss this with their prescriber.
• GnRH agonists/antagonists: no major direct interaction; cannabis can interact additively with the mood and sleep symptoms common during GnRH-induced hypoestrogenic states.
• Opioids: additive CNS depression. Some patients use cannabis to reduce opioid requirement; the trade-offs include reduced opioid burden but also unpredictable cannabis effect on acute pain.
• Benzodiazepines, sleep medications: additive sedation.

Fertility, pregnancy, and breastfeeding

Endometriosis is a leading cause of infertility; many patients pursue assisted reproductive technology. Cannabis use during the periconception period and during pregnancy is contraindicated:

• Female fertility: chronic THC exposure is associated with altered HPG axis function and possibly altered ovulation. Effects on assisted-reproductive-technology outcomes are incompletely characterized but precautionary practice is to avoid cannabis through the fertility-treatment cycle.
• Male partner fertility: chronic cannabis use is associated with lower sperm concentration, motility, and morphology in observational studies. Couples pursuing pregnancy should consider both-partner cannabis cessation.
• Pregnancy: THC crosses the placenta. Observational data link maternal cannabis use to lower birth weight, preterm birth, and possible neurodevelopmental effects.
• Breastfeeding: THC is excreted in breast milk and persists for days to weeks; the AAP and ACOG recommend against cannabis use during breastfeeding.

Population considerations

• Adolescents: endometriosis can present in adolescence; adolescent-onset chronic cannabis use is associated with elevated risk for cannabis use disorder and cognitive effects. Pediatric and adolescent endometriosis cannabis use should be a last-line consideration after standard hormonal and surgical therapy.
• Patients with co-occurring chronic pelvic pain syndromes: interstitial cystitis, irritable bowel syndrome, pudendal neuralgia, and fibromyalgia frequently overlap with endometriosis. Cannabis evidence is stronger for some of these conditions than for endometriosis specifically.
• Patients with co-occurring mental health conditions: depression, anxiety, and PTSD are common in endometriosis populations, particularly with long-delayed diagnosis. Cannabis effect on these comorbidities is variable.

State qualifying status overview

Endometriosis is explicitly listed as a qualifying condition in a growing set of states. New Jersey added endometriosis specifically in 2019, and similar legislative additions have followed in several states. As of 2026, explicit listing exists in Illinois, Pennsylvania, New Jersey, New Mexico, Connecticut, New Hampshire, Louisiana, and others. Many additional states cover endometriosis indirectly through chronic-pain or severe pelvic pain qualifiers (Arkansas, Hawaii, New York, Maryland). Discretionary-listing states (California, Oklahoma, Massachusetts, Maryland, Rhode Island, Virginia, Washington DC, Connecticut) permit physician-added certification.

State qualification is a legal-program decision. The American College of Obstetricians and Gynecologists has not endorsed cannabis as endometriosis therapy.

Practical guidance

Cannabis use in endometriosis should be adjunctive to standard hormonal and (where indicated) surgical care. Patients should continue hormonal suppression and follow up with the gynecologist on the recommended surveillance schedule. Lower-THC, higher-CBD formulations are often preferred where patients are seeking pain reduction with minimal psychoactivity. Patients planning pregnancy, pursuing fertility treatment, pregnant, or breastfeeding should not use cannabis. Cannabis use should be disclosed to all prescribers, including the gynecologist, pain-management clinician, and any reproductive endocrinology team.

Related conditions

Endometriosis overlaps clinically with chronic-pain, fibromyalgia, peripheral-neuropathy, and (less directly) anxiety-disorders. The mmjnow library covers each as a separate condition with overlapping cannabinoid-evidence considerations.

Last reviewed 2026-05-18. This is informational only — not medical or legal advice.