81%
of patients with endometriosis say it negatively affects their education, work, relationships, and physical health [1]
8 years and 10 months
is the average wait time for an endometriosis diagnosis [3]
What Causes Endometriosis?
Endometriosis is common, affecting around 10% of people with a female reproductive system. Despite how widespread it is, the exact cause of endometriosis remains unknown. One widely discussed theory is retrograde menstruation, where menstrual blood flows backwards through the fallopian tubes into the pelvis, carrying cells similar to the lining of the womb. However, this theory alone does not explain all cases.
There are several factors that may increase the likelihood of developing endometriosis, including:
- Genetics – having a close relative who has the condition increases the likelihood of also having endometriosis.
- Menstrual and reproductive history: starting periods at a younger age (less than 12 years), short menstrual cycles (less than 26 days), or not having given birth may be associated with a higher likelihood.
- Weight – some studies suggest that people with a lower body mass index may have a higher prevalence of endometriosis.
- Ethnicity – research indicates that endometriosis may be diagnosed more frequently among white/Caucasian individuals, though reasons for this are not fully understood and may be influenced by healthcare access and diagnostic disparities, rather than reflective of the true prevalence of endometriosis between ethnicities.
What are the Symptoms of Endometriosis?
The symptoms of endometriosis – and their severity – can vary widely from person to person. Common symptoms include:
- Chronic pain in the lower abdomen, pelvis, and/or lower back
- Pain during or after sex
- Pain during bowel or bladder movements
- Difficulty getting pregnant
- Nausea
- Diarrhoea or constipation
- Blood in urine or stool during a period
Many individuals also experience heavy or irregular periods and severe period pain, which can sometimes interfere with day-to-day activities.
Why is Endometriosis Painful?
Endometriosis can be painful because tissue similar to the lining of the womb grows in places where it cannot shed or leave the body in the usual way. During the menstrual cycle, this tissue can thicken and break down in response to hormonal changes, but when it is outside the uterus, it has no direct way to exit the body.
This can lead to inflammation, irritation, and the formation of scar tissue (adhesions) in areas such as the pelvis and abdomen, which contain many sensitive nerve fibres. Over time, this irritation and scar tissue can contribute to persistent or worsening pain.
Pain can vary widely between individuals but may occur around menstruation, during intercourse, when using the bowel or bladder, or at other times throughout the cycle.
How is Endometriosis Diagnosed?
For many people, receiving a diagnosis of endometriosis can take years. The condition is complex, and its symptoms can overlap with those of other conditions such as adenomyosis, irritable bowel syndrome, or uterine fibroids. Because of this, doctors often need to build a detailed picture of a patient’s symptoms over time.
During the diagnostic process, a GP may ask about symptoms and how they relate to the menstrual cycle, and they may carry out an examination of the abdomen or pelvis. In some cases, patients may be referred for further investigations, such as ultrasound scans or specialist gynaecology assessment.
Treatment Options for Endometriosis
Treatment for endometriosis will depend on a person’s symptoms, overall health, and individual circumstances. A GP may first suggest pain relief options and, in some cases, hormonal medicines such as the combined oral contraceptive pill or progestogen-only methods. These treatments aim to help manage symptoms, but their suitability varies from person to person.
If symptoms persist or are severe, a GP may refer someone to a gynaecologist for further assessment. While imaging such as ultrasound or MRI may be used to investigate symptoms, a laparoscopy (keyhole surgery) is currently the only way to confirm a diagnosis of endometriosis.
Alongside clinical treatments, some people find that diet or lifestyle adjustments provide additional support in managing symptoms. However, evidence is still emerging in this area. Therefore, these approaches are based largely on personal experience and may not be effective for everyone.
If a patient has tried other treatments without adequate relief, a specialist doctor may consider medical cannabis for symptoms such as pain and disturbed sleep, depending on clinical need and individual circumstances.
How does Endometriosis Affect People?
Endometriosis affects people in many different ways, and symptoms can vary widely. This also means that the treatments or support options that feel appropriate can differ from one person to another.
Hearing from others with lived experience can help patients feel less alone and may offer insight into the variety of approaches people explore in managing their symptoms.
"Before I joined Curaleaf Clinic, my life was dictated by pain and I’m talking decades of pain. It affects me in all aspects of my life. Curaleaf Clinic has been absolutely fantastic. Medical cannabis has changed how I run my business and helped me manage my fatigue and chronic pain.”
Medical Cannabis for Endometriosis
There is currently no cure for endometriosis, so treatment largely focuses on managing related symptoms. Some patients may have the endometrial deposits outside of the womb removed via keyhole surgery, but anywhere up to two-thirds of individuals may experience recurrence.
Some patients explore medical cannabis as a potential option when other treatments have not been effective or appropriate. Specialist doctors may consider it for unmanaged symptoms such as pelvic pain, gastrointestinal discomfort, disrupted sleep, or low mood, depending on individual clinical need.
As with any treatment, responses to medical cannabis vary, and its suitability is assessed on a case-by-case basis as part of a wider care plan.
Research Regarding Medical Cannabis and Endometriosis
Research into endometriosis and medical cannabis is still developing, but interest is growing. Researchers are exploring how the body’s endocannabinoid system may relate to endometriosis symptoms, and a combination of laboratory studies and real-world evidence is helping to shape future research questions.
Clinical and Real-World Evidence
Laboratory and preclinical studies have examined how cannabinoids interact with biological pathways linked to pain and inflammation in endometriosis [4,5]. These findings are early-stage and do not directly translate into proven clinical outcomes.
Real-world evidence adds another perspective. The UK Medical Cannabis Registry, led by Curaleaf Clinic’s research team, has published a longitudinal study following patients with endometriosis who were prescribed medical cannabis and reported their symptoms over time [6]. While observational and unable to show direct cause and effect, this research helps build a clearer picture of patient-reported experiences, patterns of use, and tolerability in clinical practice.
The Endocannabinoid System and Endometriosis
The endocannabinoid system (ECS) helps regulate processes such as pain, inflammation, and mood. Research suggests the ECS may behave differently in people with endometriosis, including differences in the expression of cannabinoid receptors such as CB1 and CB2 [4].
These observations have led some researchers to explore whether ECS pathways may influence how endometriosis symptoms are experienced. However, the relationship is not fully understood, and more research is required before firm conclusions can be drawn.
Can I be Prescribed Medical Cannabis for Endometriosis?
Endometriosis can be difficult to diagnose and manage, and treatment is often holistic – involving a combination of medical, lifestyle, and supportive approaches. Medical cannabis may be considered when other options haven’t been suitable or haven’t provided adequate symptom relief.
If you’d like to explore whether medical cannabis is appropriate for you, you can complete an eligibility assessment with Curaleaf Clinic.
We’ll review your full GP and specialist records and, if appropriate, invite you to meet with one of our pain specialists who has experience supporting patients with endometriosis.
References
[1] https://pmc.ncbi.nlm.nih.gov/articles/PMC9047767/
[2] Opinium poll, 4000 UK adults, February 2025 – 07 February 2025
[3] https://www.endometriosis-uk.org/endometriosis-facts-and-figures
[4] https://pmc.ncbi.nlm.nih.gov/articles/PMC2972363/
[5] https://www.sciencedirect.com/science/article/pii/S0165614724002153
[6] https://obgyn.onlinelibrary.wiley.com/doi/10.1111/ajo.70078