AbstractIn biological research, new ideas arise and quickly spread to encompass the entire field. Thus, the evolution of molecular biology has significantly changed our methods of approaching our research. A similar far‐reaching finding has been the advent of radical reactions into biology. Although radical chemistry has been utilzed for many technological advances that affect our daily lives, the appreciation of this same process within our cells has opened an unexplored arena for research enquiry. As cellular messengers, radical molecules seem shimsically designed: they are evanescent, rapidly and apparently indiscriminately reactive, and barely detectable bymost biological methods. Yet, our initial probing of these reactive agents in cells and organisms has led us to postulate a virtually undescribed system of communication within and among cells which may have significant effects in multiple organs. In bone, radical reactions have been attributed with an important role in the control of bone resorption.