Genitourinary syndrome of menopause (GSM) is a chronic, oestrogen-deficient condition that is frequently underdiagnosed and undertreated. Although low-dose vaginal estriol improves epithelial trophism and microbial balance, a substantial proportion of women report persistent symptoms. High-quality randomised evidence evaluating combined therapeutic strategies remains scarce. Energy-based modalities, including the erbium:YAG (Er:YAG) laser (=2940 nm), have been proposed as adjunctive treatments. This trial aims to assess the efficacy of Er:YAG laser therapy combined with vaginal estriol compared with estriol alone in postmenopausal women with GSM.

This is a single-centre, randomised, double-blind, controlled clinical trial. Postmenopausal women aged 45–70 years with vaginal pH ≥5.0 and at least one moderate GSM symptom (Visual Analogue Scale ≥4) will be eligible. Exclusion criteria include current systemic or local hormone therapy, previous vaginal energy-based treatment, abnormal cervical cytology and body mass index ≥35 kg/m². All participants will receive vaginal estriol cream (0.5 mg per dose) daily for 14 days, followed by twice-weekly administration for 16 weeks. Participants will be randomised (1:1) to receive either estriol plus sham Er:YAG laser or estriol plus active Er:YAG laser. Three laser sessions will be delivered at approximately 4-week intervals. Assessments will occur at baseline, monthly during treatment and 4 months after the final session. The primary outcome is the Vulvovaginal Health Index, with the primary endpoint defined as the change from baseline to 4 months post-treatment, reflecting sustained effect. Secondary outcomes include GSM symptom severity, vaginal microbiome composition (16S rRNA sequencing), quality of life (Menopause Rating Scale) and sexual function (Female Sexual Function Index). Data will be analysed using repeated-measures analysis of variance or appropriate non-parametric tests, with significance set at p

Ethical approval has been obtained from the Human Research Ethics Committee of UNINOVE. Written informed consent will be obtained. Findings will be disseminated via peer-reviewed journals and scientific meetings.

NCT06873971.