Introduction: In recent years, considerable attention has been paid to isoflavones and their proprieties to alleviate the climacteric symptoms. The goal of this study was to evaluate the efficacy of standardized isoflavones extract (SoyfemR) in moderate and medium-severe climacteric syndrome. Material and methods: 555 postmenopausal women were recruited for the study. Out of this group, 169 women completed the study (12- month observation period). The patients were classified according to the intensity of climacteric symptoms (≤34 points in Kupperman index). 1 or 2 tablets of SoyfemR were administered twice a day. Results: A regular decrease of Kupperman index value and improvement of life quality were observed in the group of 169 postmenopausal women. We have noted a decrease in the intensity and number of hot flushes, diaphoresis (p<0,05), diminished sleep disturbances (p<0,05), decreased headache, dizziness, and arthrosis pain. The diminished intensity of tiredness, palpitation and breathlessness have been also observed (p<0,05). 80% of all investigated women noted the regression of paresthesis, 20% indicated the decreased number of paresthesis (p<0,05). Influence of SoyfemR on the variability and moderation of depressive mood (p<0,05) have been also positive evaluated by patients. Conclusions: Administration of SoyfemR in the dosage 52 to 104mg/24 hours (2 times daily 1 or 2 tablets) is a safe and effective therapy in the postmenopausal women with moderate and medium-severe climacteric syndrome evaluated according to the Kupperman index. Administration of SoyfemR is connected with a good compliance and correlated with well-being in the investigated women allowing a long-term administration.