Ethylenediamine dihydroiodide (EDDI) is primarily utilized as an iodine supplement in animal feed to prevent iodine deficiency in livestock, supporting thyroid function and overall health. It is also employed in pharmaceutical applications as an expectorant in cough syrups and respiratory treatments to help clear mucus. In organic synthesis, it serves as a source of ethylenediamine for chelating agents or ligands in coordination chemistry, and as an iodide donor in specific iodination reactions. Additionally, it finds use in niche laboratory applications involving nitrogen-iodine chemistry.