Millions of women live with the chronic pain, fatigue and inflammation of endometriosis. Now experts are investigating whether GLP-1 medications could have benefits beyond weight loss – but the evidence is still in its infancy
For many women living with endometriosis, relief can be frustratingly elusive.
The chronic condition, which affects an estimated 190 million women and people assigned female at birth worldwide, occurs when tissue similar to the lining of the uterus grows outside the womb, triggering inflammation, scarring and often debilitating pain.
Symptoms can include severe period pain, pelvic pain, bloating, painful sex, fatigue and fertility problems, while diagnosis can frequently take years.
Treatment options have changed surprisingly little over the past decade. Hormonal therapies can suppress symptoms, surgery may remove lesions, and pain medication can help manage flare-ups, but none represents a cure.
So when some women taking GLP-1 medications for diabetes or weight loss began reporting that their endometriosis symptoms seemed to improve, doctors and researchers began to take notice.
Could drugs such as semaglutide and tirzepatide have an unexpected role to play in one of women’s most challenging chronic conditions?
An unexpected observation
GLP-1 receptor agonists – including semaglutide, found in drugs such as Ozempic and Wegovy, and tirzepatide, the active ingredient in Mounjaro – were developed to improve blood sugar control before becoming widely used for obesity.
More recently, research has identified benefits extending beyond weight loss, with evidence supporting their use in areas including cardiovascular disease, kidney disease, fatty liver disease and sleep apnoea.
Now endometriosis has emerged as another condition attracting scientific interest.
Doctors specialising in endometriosis have reported hearing from patients who experienced reductions in pelvic pain, bloating and inflammatory flare-ups while taking GLP-1 medications. These reports remain anecdotal, but they have prompted researchers to investigate whether there could be a genuine biological explanation.
Jo Sandwell, consultant gynaecologist and endometriosis surgeon at Guy’s and St Thomas’ NHS Foundation Trust and HCA hospitals, stresses that the experience is unlikely to be universal.
“As an endometriosis surgeon I have observed that endometriosis is a disease with great heterogeneity,” she says. “No two women are the same and it is important to know that although some women report a benefit, others have not.”
That variability is important because endometriosis is increasingly understood as a complex disease involving much more than reproductive hormones alone.
Why might GLP-1 drugs help?
The traditional view of endometriosis focused primarily on hormones, particularly oestrogen. Today, however, researchers increasingly recognise it as a chronic inflammatory disease involving complex interactions between the immune system, inflammatory signalling and abnormal tissue growth.
That shift in understanding makes GLP-1 drugs particularly intriguing.
Although best known for reducing appetite and improving blood sugar regulation, GLP-1 receptor agonists also appear to influence inflammatory pathways throughout the body. Laboratory and animal studies suggest they may reduce inflammatory signalling, alter immune cell activity and dampen chronic inflammation – processes thought to play a role in endometriosis.
Sandwell believes there are several plausible explanations for why some women might experience an improvement.
“Reduced fat tissue from weight loss means that women are producing less oestrogen which is the main driver of endometriosis,” she explains.
But she believes weight loss may not be the whole story.
“There also is evidence of an increase in sensitivity of endometrial type cells to progestogens which are one of the main treatments for endometriosis.”
Inflammation could provide another potential link.
“The reduction in inflammatory messengers seen with GLP-1s may also drive some of the response,” says Sandwell. “Endometriosis produces inflammation within peritoneal fluid… and so it is plausible that reducing this inflammation may help reduce pain.”
It is an intriguing hypothesis, particularly because some researchers have proposed that GLP-1 medications could influence several of the biological processes involved in endometriosis, including inflammation, immune dysfunction, fibrosis and chronic pain.
But there is an important distinction between a plausible mechanism and a proven treatment.
More than just weight loss?
One of the biggest questions researchers are trying to answer is whether any improvement is simply a consequence of losing weight.
Obesity can increase levels of inflammatory chemicals within the body, and reducing excess weight may naturally lessen systemic inflammation. However, researchers are also exploring whether GLP-1 medications possess anti-inflammatory effects that occur independently of weight loss.
That could potentially explain why some women report improvements that seem disproportionate to changes in body weight.
But at this stage, this remains an area for investigation rather than established medical fact.
Sandwell is clear that much more evidence is needed before GLP-1 medications could be considered as a treatment for endometriosis.
What does the evidence actually show?
This is where caution is essential. There are currently no large randomised clinical trials demonstrating that GLP-1 medications treat endometriosis.
Most of the excitement comes from patient reports describing symptom improvements, laboratory and animal research, evidence surrounding the drugs’ anti-inflammatory mechanisms and reviews proposing plausible biological pathways.
Together, these provide a compelling rationale for further research. They do not, however, prove that GLP-1 drugs reduce endometriosis pain or slow disease progression in people.
For Sandwell, the next step is clear.
“The gold standard for any treatment is always a double blind randomised controlled trial, ideally with large numbers of women at multiple centres,” she says.
Such research could establish whether the benefits reported by some women are genuinely caused by GLP-1 medication, whether they are primarily related to weight loss, or whether there are particular groups of women who might respond better than others.
Should women with endometriosis ask for GLP-1 drugs?
For now, Sandwell’s answer is emphatic. “Absolutely not,” she says. “We are only at the very beginning of understanding the way in which GLP-1 could help some women with endometriosis.”
She believes that, if the research eventually proves a benefit, the drugs are unlikely to become a first-line treatment for everyone with endometriosis.
“I suspect that in the future they are unlikely be used first line for all women with endometriosis but could be used in selected patients,” she says.
The challenge is identifying who those patients might be and what benefit they could potentially achieve.
“Until we understand that I would not recommend starting GLP-1’s to treat endometriosis.”
There are practical considerations, too. Sandwell notes that GLP-1 medications are not recommended when trying to conceive, while their effect on stomach emptying can also affect the absorption and effectiveness of some medications used for endometriosis, including contraceptive pills.
A promising new direction – for now
For decades, advances in endometriosis treatment have been frustratingly slow despite the condition affecting millions of women worldwide.
The possibility that medications originally developed for diabetes – and subsequently transformed the treatment of obesity – could also influence the inflammatory processes associated with endometriosis represents an intriguing new avenue of research.
But it is important not to get ahead of the science.
The reports from women experiencing improvements are worth investigating. The biological mechanisms are plausible. The early research is interesting.
What is missing is the clinical evidence needed to turn that promise into treatment.
For women living with endometriosis, that means GLP-1 medications should not currently be viewed as a new cure or a reason to seek out weight-loss drugs.
But if future trials confirm what researchers are beginning to suspect, they could eventually become another tool in the fight against one of women’s most painful and poorly understood conditions.
