Endometriosis is a chronic, estrogen-dependent condition frequently associated with pelvic pain and reduced quality of life. Relugolix combination therapy (CT), an oral GnRH receptor antagonist-based treatment, has demonstrated efficacy in randomized clinical trials, but real-world data remain limited.

The RELAX study is a single-center, ambispective observational study evaluating the effectiveness of relugolix CT in reducing endometriosis-associated pain over 24 weeks in routine clinical practice. The primary endpoint is the change from baseline in pelvic pain measured by the Visual Analog Scale (VAS). Secondary outcomes include changes in pain-related symptoms, ultrasonographic findings, patient satisfaction, and safety.

Endometriosis is a chronic, estrogen-dependent condition frequently associated with pelvic pain and impaired quality of life. Despite available hormonal treatments, unmet clinical needs remain in terms of long-term efficacy and tolerability. Relugolix combination therapy (CT), an oral GnRH receptor antagonist combined with estradiol and norethisterone acetate, has shown efficacy in randomized trials, but real-world data are limited.

The RELAX study is a single-center, ambispective observational study evaluating the effectiveness of relugolix CT in routine clinical practice. Women aged 18-50 years with laparoscopically or radiologically confirmed endometriosis receiving relugolix CT will be included. Both retrospective and prospective data will be collected.

The primary objective is to assess the change from baseline in chronic pelvic pain measured by the Visual Analog Scale (VAS) after 24 weeks of treatment. Secondary outcomes include changes in dyspareunia, dyschezia, and dysuria; the proportion of patients achieving ≥30% and ≥50% reduction in VAS pain score; changes in transvaginal ultrasound findings; patient satisfaction; and safety.

This study aims to provide real-world evidence to support clinical decision-making in the management of endometriosis-associated pain.

Inclusion Criteria:

• Female aged between 18 and 50 years
• Endometriosis confirmed laparoscopically or radiologically (via ultrasound or MRI)
• Receiving treatment with Relugolix CT according to clinical practice for at least one month
• Pain score ≥40 on the VAS scale
• Regular menstrual cycles, (i.e., not in a menopausal or perimenopausal state)
• Signed informed consent

Exclusion Criteria:

- Menopausal status (natural or surgical)

Patients with a diagnosis of endometriosis who have been receiving treatment with Relugolix CT according to clinical practice for at least one month.