Endometriosis & Medical Cannabis: What We Know

Endometriosis is a painful condition that affects one-in-nine women and people assigned female at birth – more than 830,000 people in Australia alone. Endometriosis (or endo as it’s commonly known) occurs when tissue similar to the womb’s lining (endometrium) grows in other parts of the body. The result can be pelvic pain, inflammation, organ damage and even infertility.

Yet the causes, symptoms and potential cures for the disease remain poorly understood. According to Endometriosis Australia, most women wait more than 6 years for an accurate diagnosis and when it comes to treatment, the options can be invasive or have unpleasant side-effects.

For this reason, there has been a renewed interest in complementary therapies for women struggling with endometriosis, including medical cannabis – both for its analgesic (i.e. pain relieving) properties, as well as for being a potential treatment for the disease itself.

What Is Endometriosis?

Endometriosis is caused by endometrial cells growing outside of the fallopian tubes. This happens most commonly around the pelvic region, including the ovaries, pelvis and bladder, but can occur anywhere in the body. The tissue still behaves like the womb’s lining, which means that every month it becomes inflamed and bleeds. Over time, this leads to scarring and inflammation and can cause organs in the pelvis to adhere to each other.

Endometriosis can start from puberty and last until after menopause. Unfortunately, it’s often progressive, meaning symptoms get worse over time. There are four stages of endometriosis, from mild, with only small patches of endometriosis, to severe, where it has spread to most of the pelvic organs.

Endometriosis can affect anybody assigned female at birth, including transgender and non-binary people. It has a significant impact across Australia, with research showing it leads to billions of dollars of lost productivity.

Symptoms Of Endometriosis

Pain and infertility are the two main symptoms of endometriosis, but everyone’s experience will be unique. Not everyone will have all of these symptoms, and about a quarter of people with endometriosis experience no symptoms at all.

Endometriosis is most well known for causing abdominal and pelvic pain, particularly around a person’s period. Pain can also occur when having sex or going to the toilet. The severity and type of pain depends on where the endometriosis is and how long it has been growing.

Over time, endometriosis can also lead to infertility – one study reports that infertility occurs in between 30–50 percent of people with the disease. The anatomical, hormonal, inflammation and immune system changes associated with endometriosis can contribute to infertility, but the exact mechanisms aren’t well understood.

Other symptoms of endometriosis can include:

• Heavy periods or irregular bleeding
• Bleeding from the bladder or bowel
• Gastrointestinal issues
• Bloating
• Fatigue

Causes Of Endometriosis

There are two primary causes of endometriosis that we know of. Firstly, menstrual blood can pass back through the fallopian tubes and into the pelvic cavity. Because this blood contains endometrial cells, it can start growing and cause endometriosis. Secondly, normal pelvic tissue can turn into endometrium in a process called metaplasia.

However, we don’t understand exactly why this happens to some women and not others. We do know that there are risk factors that make someone more likely to have endometriosis, including:

• Having a family history of endometriosis
• Starting your period before the age of 11
• Getting pregnant for the first time when you are older
• Having immune system issues
• Alcohol use

Treatments For Endometriosis

Unfortunately, there is no cure for endometriosis. However, once it has been diagnosed, patients can work with their doctor to find ways to manage the symptoms.

Standard medical treatments for endometriosis include hormone treatments, pain relief (especially opioids) and surgical removal of endometriosis tissue. For some people, a hormonal contraceptive like the pill or implant can reduce symptoms, which is often combined with lifestyle changes to reduce inflammation and rebalance the body’s hormonal system. Psychological care can also be prescribed to help people manage the distress associated with chronic pain.

“As a person living with endometriosis and the impact it has left on my body, I know all too well how often we struggle to find effective treatment options. Using medical cannabis under the care of my GP, I’ve found it has helped me manage some of my symptoms.” – Donna Ciccia, Director of Chronic Pain Australia

Medical Cannabis & Pain Relief

Since 2016, more than 400,000 Australians have received prescriptions for medical cannabis – and almost two-thirds of those have been for the management of chronic pain.

Reviews of the scientific literature find a consistent improvement in reported pain levels among patients using medical cannabis, especially those using THC-dominant products. However, those reviews also emphasise the early stage of the research and the need for more and better studies to fully understand the mechanism behind cannabis pain-relieving properties.

Perhaps more compelling are self-reported quality of life surveys. An Australian study tracked more than 3000 chronic pain patients for four years to gauge how using medical cannabis affected their quality of life. The authors found that medical cannabis use was associated with “significant improvements” in reported quality of life, which were mostly sustained over time.

Similarly, in a 2023 survey of more than 2900 chronic pain patients conducted by Montu, almost 9-in-10 reported a positive effect on their quality of life, while 96% found cannabis to be a somewhat or very effective treatment for pain, with an average reduction in reported pain of more than 30%. Tellingly, almost two-thirds of respondents also said they had stopped using other pain management medications.

Treating Endometriosis With Medical Cannabis

While the literature specifically examining endometriosis and cannabis is still in its infancy, there are some encouraging signs. In a 2017 survey of 484 Australian women with endometriosis, cannabis and CBD oil were the highest rated “self-management” interventions, despite only being used by 1-in-10 participants.

A 2021 Canadian study took self-reported symptom management data from 252 women and found that cannabis was an effective tool for the treatment of pain, gastrointestinal issues and diminished mood. Interestingly, they found that pain responded better to inhaled cannabis, while gastrointestinal and mood-related symptoms were managed better by orally consumed oils and edibles. In a New Zealand study on cannabis and endometriosis from 2019, more than half of the respondents said that they had ceased other medications since beginning medical cannabis treatment.

In a 2022 study for the International Journal of Molecular Sciences, an Italian team looked at the molecular interaction between CBD and endometriosis cells in rats. While not a human study, the researchers found that CBD “significantly reduced” endometriosis growth and modified the cells to make them less able to spread.

While promising, all these studies emphasise the need for bigger and more targeted human studies to be urgently conducted.

Managing Your Endometriosis: A Holistic Approach

Endometriosis affects hundreds of thousands of Australian women, often causing significant distress and discomfort. While there is no cure, working together with your doctor to create a holistic treatment plan can help you improve your quality of life significantly. If you believe medical cannabis could be part of your endometriosis treatment plan, book an appointment with your GP or a dedicated medical cannabis clinic to discuss your options.