Osteoporosis is a bone disease characterized by low bone mass which makes the bones susceptible to fractures. Icariin is a type of flavonoid that promotes osteocyte differentiation and inhibits the formation of osteoclasts which lowers the bone resorption rate. Numerous data indicate that flavonoids including icariin have strong antioxidant, phytoestrogen and antiosteoporotic properties. The main objectives of this thesis are: (i) promoting osteoporosis in rats with high dosis of retinoic acid, (ii) evaluating icariin's ability as a therapeutic in RMO, (iii) comparing the effects of icariin to a commercial drug-alendronate, (iv) investigating icariin's antioxidative abilities on the ovaries, (v) assessing icariin's effect on the skeletal system of RMO and healthy rats as well as (vi) comparing the genotoxicity of icariin and alendronate in RMO and healthy rats. Our results indicate that icariin increases bone mass and mass of uterus, as well as bone mineral density through antioxidant and estrogenic activity. Icarin shows smaller genotoxic effects of alendronate.