The effect of progesterone therapy on E2/P ratio changes during the luteal phase, and its consequences are on mastalgia and cyst, within a fibrocystic breast disease (FBD). Fifty women with FBD were included. Information for mastalgia and mastodynia were checked with a questionnaire. All women had (E2) and (P) concentration checked before and during the therapy on the 21st and 24th day of a cycle, ultrasound measured size and number of cysts before and during the therapy. T-test, X 2-test, McNemar test, Wilcoxon test and Friedman test were used for statistics. There was a decrease E2/P relation during the therapy vs. before the treatment p < 0.01, as well as the decrease of E2 level on the 24th day during the therapy vs. same day of E2 level, before the therapy (p = 0.164). There was an increase of p level on the 24th day vs. on 24th day before the therapy (p < 0.001). During the therapy, it was found decrease in pain and tension (p < 0.001), and the number and size of the cysts (p < 0.001). Mastalgia and mastodynia significantly decreased during the local p gel therapy, and there was a significantly lower number and size of the cysts in patients with FBD.