A degradable composition including magnesium-based materials doped with metals, metalloids, and/or compounds, where the composition has a hardness in excess of 80 BHN, and methods of using the same (for example, as a constituent of a treatment fluid of a subterranean formation) are described. The degradable composition may be a shaped composition that degrades in environments typically encountered downhole, such as oilfield environments/conditions and/or fluids. Compositions including magnesium-based materials and various manufacturing processes to produce a composition including the magnesium-based materials in a desired shape are also described.