MYTH: "Endometriosis is a hormonal disease"

“Endometriosis is a hormonal disease” - hands up if you have heard this!

Say it with me…. 

While our hormone oestrogen strongly stimulates the growth of endometriosis lesions, endometriosis itself is not caused by excess oestrogen. Endometriosis is a complex inflammatory disease characterized by: 

  • Immune dysfunction: high levels of cytokines including Il-8 & TNF-a promote endometrial cell proliferation adhesion and angiogenesis, or blood supply to the lesions. Endometriosis shares similarities with other autoimmune conditions including rheumatoid arthritis, Crohn’s disease and psoriasis. 

  • Bacterial contamination hypothesis: “bad bacteria” can translocate or move from the gut to the pelvis. Research has shown that women with endometriosis have a high level of gram-negative bacteria in the pelvic microbiome.  These bacteria contain the toxin LPS (lipopolysaccharide), which promotes the onset and progression of lesions. This movement of bacteria is likely to occur in cases of increased intestinal permeability or “leaky gut” and small intestinal bacterial overgrowth (SIBO). This bacterial contamination activates the immune response. Women with endometriosis have been shown to have elevated levels of the following bacteria in the gastrointestinal microbiome:

    • Enterobacteriaceae

    • Streptococcus

    • E.coli

    • Gardnerella


Modulating our hormones or encouraging clearance of oestrogen relative to progesterone is still an important part of endometriosis treatment, but it should not be the ONLY treatment strategy. That’s why the oral contraceptive pill, although potentially helpful in suppressing oestrogen production and symptom suppression, cannot be used to cure endometriosis - because as soon as the OCP is stopped, the cycle starts again. In order to treat endometriosis, a holistic approach is needed - and that includes treating the immune system, reducing inflammation and modifying the gastrointestinal microbiome and supporting healthy hormone balance.


Endometriosis is a complex condition - reach out if you need support.

Hayley Brass