Abstract Introduction There is no study assessing the changes in sexual health after risk reducing oopherectomy in premenopausal women. Objective Objective: To evaluate the effect of risk-reducing salpingo-oophorectomy (RRSO) on change in sexual function in women aged 34-50 years with pathogenic variants in BRCA1 or BRCA2 (BRCA1/2). Methods Methods: The PROSper (Prospective Research of Outcomes after Salpingo-oophorectomy) study is a prospective cohort of women aged 34-50 years with BRCA1 or two germline pathogenic variants that compares health outcomes after RRSO to a non-RRSO control group with ovarian conservation. Women aged 34-50 years, who were planning either RRSO or ovarian conservation, were enrolled for 3 years of follow-up. Sexual Function was measured using the Sexual Health Outcomes in Women (SHOW-Q) a validated survey tool that measures sexual desire, frequency, satisfaction, orgasm, and discomfort specifically in patients with a history of a pelvic condition, including oophorectomy. Differences in sexual function between the RRSO and non-RRSO groups, were determined by using mixed effects multivariable linear regression models. Results Results: Of 100 PROSper participants, all completed SHOW Q. At baseline patients who had undergone RRSO before enrollment had lower SHOW-Q scores (71 vs 64). Across all 60 months of the study the SHOW-Q scores remained persistently lower in those undergoing RRSO raging from 6-13 points across the time studied (p <0.05) controlling for age, depression, partner, menopausal symptoms and hormone therapy Conclusions Conclusion: Women with pathogenic variants in BRCA1/2 who undergo RRSO before the age of 50 years have greater effects on sexual function than those that do not. The detrimental effect of rRRSO is not otherwise explained by hormone therapy, depression or menopausal symptoms. This information should be incorporated into counseling and post op management to consider options to improve sexual health post surgery Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: sprout pharma.