The invention provides compositions for producing hydrogen rich water, nutraceuticals, cosmetics, pharmaceuticals, and other products. In one embodiment, the invention provides a composition, e.g., a tablet, including magnesium metal, at least one water-soluble acid, and a binding agent. The magnesium metal and at least one water-soluble acid may be present in amounts sufficient to maintain a pH of less than 7, e.g., at a specific time period after reaction, and a concentration of at least 0.5 mM H2 after reaction in 50 mL water in a container e.g., a sealed or an open container, e.g., at least 0.5 mM H2 after reaction in 100 mL water or at least 0.5 mM H2 after reaction in 500 mL water. The composition may also include a lubricant.
