Objective: There is a lack of safety data supporting the use of hormone therapy in women who have had breast cancer and who have complained of genitourinary syndrome of menopause (GSM). The objective was to test the efficacy of two non-hormonal therapies for vaginal dryness. Methods: This was a randomized trial with 52 women with breast cancer who were being treated with tamoxifen and who complained of vaginal dryness. The volunteers answered two questionnaires to evaluate sexual function (Female Sexual Function Index, FSFI) and a customized GSM questionnaire. The women were randomized into two groups: 25 (48.1%) in the polyacrylic acid group and 27 (51.9%) in the lubricant group, using either one of the treatments for 30 days, and after they were invited to answer the questionnaires again. Results: There was improvement in the FSFI after both treatments. The polyacrylic acid group showed a decrease in sexual dysfunction from 96% to 24% (p < 0.0001) and the lubricant group showed a decrease from 88.9% to 55.6% (p = 0.0027). Conclusions: The results of this study showed that both treatments improved sexual function; however, polyacrylic acid was superior to the lubricant in treating sexual dysfunction.