Cu(II) protoporphyrin IX is widely used in biochemical research as a model compound to study the properties and behavior of heme-containing proteins, such as hemoglobin and cytochrome P450 enzymes. Its structure closely mimics that of natural heme, making it valuable for investigating electron transfer processes, oxygen binding, and enzymatic reactions. In medical research, it is employed to explore the mechanisms of diseases related to heme metabolism, such as porphyrias. Additionally, it serves as a photosensitizer in photodynamic therapy, where it generates reactive oxygen species to target and destroy cancer cells or pathogens. Its stability and functionality also make it useful in the development of biosensors and biomimetic catalysts for industrial applications.