The invention encompasses compositions and methods for effectively treating and/or preventing the development and/or progression of osteoporosis and related disorders such as osteoarthritis and rheumatoid arthritis, and for promoting overall bone and joint health. This is accomplished by addressing multiple key mechanisms that lead to such disorders. The invention includes compositions comprising a combination of agents having biological activities that effectively suppress, regulate or interfere with the various key biochemical processes and mechanisms that increase the risk for development and/or progression of osteoporosis. The present compositions and methods simultaneously promote bone formation and reduce bone resorption by (a) stimulating osteoblast formation and osteogenesis； (b) suppressing adipocyte differentiation； (c) inhibiting osteoclast formation； and (d) increasing apoptosis of osteoclasts. The inventive compositions used for administration to human and other mammalian subjects having or at risk for development of osteoporosis comprise (1) at least one agent capable of modulating expression and/or activity of one or more of peroxisome activated protein receptor gamma (PPAR-γ), CAAT/enhancer binding protein-α (C/EBPα) and Sterol Regulatory Element-Binding Protein (SREBP-1)； (2) at least one agent that activates expression and/or activity of one or more of the osteogenic transcription factors (Runx2/Cbfα1, Dlx5, Osterix, Msx2)； (3) at least one agent that activates expression and/or activity of one or more of bone morphogenetic proteins (BMPs: BMP 2 and 4), alkaline phosphatase (ALP), and osteocalcin； (4) at least one agent capable of activating Wnt/β-catenin signaling pathway； (5) at least one agent that inhibits the activity of pro-oxidants including reactive nitrogen species and reactive oxygen species (ROS)； (6) at least one agent that suppresses one or more of inflammatory mediators including interleukins IL-1α, IL-1β, IL-6, NF-κB, TNF-α, matrix m
