Abstract
Diagnosis of endometriosis remains challenging, as the diagnostic delay is still encountered. This phenomenon is in accordance with the reported cases, in which the definitive diagnosis is approximately issued by 7—12 years delayed onset of symptoms. Many findings have reported several putative biomarkers from various resources, but no single biomarker displayed enough accuracy to be used outside the research setting. As the primary source of retrograde menstruation, identifying the constituents of menstrual blood may provide critical information on the pathogenicity and dysregulation occurring in the endometrium milieu. Indeed, the recent findings on menstrual biomarkers have demonstrated significant progress in the quest for new alternative sources to diagnose endometriosis. Further research with a combination of different approaches and integrated panel biomarkers is needed to bring the menstrual blood biomarkers step forward to clinical application. Here, we reviewed the menstrual biomarkers that have been reported to date, unlocking the potential utility of menstrual blood to develop an early, noninvasive diagnosis of endometriosis.