A fresh study has looked into whether medicinal cannabis could provide a new treatment option for those living with endometriosis.
It’s estimated that 120,000 women in NZ are living with endometriosis, an inflammatory disease where tissue similar to the uterine lining is found outside the womb.
Symptoms include severe and debilitating menstrual pain, non-cyclical pelvic pain, fatigue and reduced fertility.
A study conducted by the University of Otago, led by Dr Claire Henry from the Department of Surgery and Critical Care, involved 28 participants suffering from endometriosis and/or related pelvic pain.
The participants were prescribed cannabidiol (CBD) oil, either on its own or in combination with dried cannabis flower, for a duration of three months.
Results from the study showed that it reduced pain, improved sleep and lowered anxiety.
Participants recorded their weekly pain scores on a numerical scale, where 0 indicated no pain, and 10 represented the worst pain imaginable.
Additionally, they completed an endometriosis health profile questionnaire both before the trial began and at the end of the 12 weeks.
Seventeen were interviewed about their experiences at the end of the study.
Henry said overall pelvic pain among the group dropped from a level of 5.4 to 3.7, and the level of the worst pain dropped from 7.6 to 5.3.
There was also a clinically meaningful improvement in their health-related quality of life scores.
Henry said while CBD did not work for everyone, for some, the impacts had been life-changing.
One participant talked of preparing to re-enter the workforce after three years out, while another said they were “in such a good place health-wise [they were] starting to try to have a baby”.
The benefits on their sleep and anxiety had an almost equal effect on their quality of life as the reduction in pain.
Henry said the current treatment for endometriosis included pain management, hormonal medications and surgery.
“However, medical management of endometriosis is often associated with side effects, and patient satisfaction with these treatments can be limited,” she said.
Those in the trial were also using personalised combinations of analgesic, contraceptive, and holistic medication, as well as lifestyle modifications in an attempt to self-manage their pain.
Several of the participants reported previously using opioid-based analgesics, including tramadol, but said it provided limited or inconsistent relief and was often accompanied by undesirable side effects, including nausea, dizziness and fatigue.
The study showed there were few side effects reported from CBD use, with participants perceiving it as a gentler alternative that could still offer effective symptom relief.
The research project was supported by funding from the endometriosis support group Endo Warriors Aotearoa.
The founder, Yessenia Sandoval, said the study highlighted the need for accessible, evidence-informed care pathways for endometriosis.
“Those with endometriosis find it really difficult to find medications that work, that are affordable, and that don’t come with unmanageable side effects.”
Henry said large-scale studies and clinical trials are needed so the safety, efficacy and long-term effects of using medicinal cannabis to treat endometriosis-related pain can be further evaluated.
“In particular, it is important to understand how medicinal cannabis treats pain and for whom it would work best.
“Endometriosis pain management is often complex and individualised, and while CDB had benefits in terms of pain relief and improved sleep for many of our participants, we still need to understand how it works and what the long-term effects from its use might be.”