Background: Polycystic ovary syndrome (PCOS) and obesity have been linked to impaired sexual function. This study investigated changes in sexual function in women with obesity with and without PCOS after metabolic bariatric surgery.

Methods: We conducted a prospective cohort study of women with obesity who underwent metabolic bariatric surgery, comparing those with (OP) and without (ONP) PCOS. A control group of healthy women without obesity was also included. Sexual function (McCoy Female Sexuality Questionnaire; MFSQ), psychiatric health (Mini International Neuropsychiatric Interview; MINI), menstrual pattern, and testosterone hormone levels were assessed pre-surgery and 12 months post-surgery.

Results: The study included 104 women: 67 with obesity (38 OP, 29 ONP) who underwent metabolic bariatric surgery and 26 healthy controls. Before surgery, both obese groups had lower MFSQ scores (OP: 48 [36.5–54]; ONP: 38 [32–48]) compared to control (52.5 [45.75–56.25]; p = 0.001), with no difference between OP and ONP. The OP group had higher testosterone, free androgen index (FAI), hirsutism, and menstrual irregularity (all p < 0.001) than other groups, these factors improved post-surgery. MINI scores showed no group differences pre- or post-surgery. After surgery, sexual function improved in both obese groups, aligning with control. Summed MFSQ scores rose significantly only in ONP (p = 0.031). Satisfaction with frequency of sexual activity improved in both groups; sexual thoughts improved only in ONP. Lubrication was greater in OP (p = 0.019), while orgasm frequency remained lower in both obese groups (p = 0.029). In OP, BMI was negatively linked to MFSQ (β = -0.864, p = 0.005).

Conclusions: Metabolic bariatric surgery improves sexual function and PCOS symptoms in women with obesity, potentially linked to BMI reduction. Mental health and testosterone levels were not associated with sexual function in this sample, though these null findings should be interpreted cautiously.