Osteoporosis is a disease of the skeletal system caused by disturbances in the equilibrium between formation and degradation of bone tissue in favor decomposition. With extending life expectancy, the incidence of osteoporosis began to grow, leading to increased research into pathogenesis of osteoporosis and development of drugs or therapeutics against osteoporosis. In this study, we investigated the effect of proanthocyanidins in the treatment of osteoporosis induced by retinoic acid in the rat model. We caused osteoporosis in rats by intragastric use of 13-cis retinoic acid (13cRA, 80 mg kg-1) for 15 days, and then applied proanthocyanidin (100 mg kg-1) or alendronate (positive control, 40 mg kg-1) for the next 15 days. We have explored effectiveness of proanthocyanidins by monitoring of changes in mass of animals, analysis of femur’s physical factors (weight, length and diameter), measurement of bone mineral density of femur’s metaphysis, determination of calcium and phosphorus in bone and hematological and biochemical analysis. Antioxidant and anti-inflammatory effect of proanthocyanidins was determined by analyzing the relative weight of animals, the rate of lipid peroxidation and glutathione concentrations in the kidney, liver and ovaries. Phytoestrogens impact was estimated based on the relative weight of the uterus. The results show a significant antioxidant, anti-inflammatory, phytoestrogens and antiosteoporotic effect of proanthocyanidins in animal models of osteoporosis. The absence of the negative consequences of proanthocyanidins and their easy accessibility gives them an advantage in the treatment of osteoporosis compared to alendronate.