Protease-Activated Receptor-4 (PAR-4) activating peptide is a synthetic specialty chemical reagent used in biochemical research to selectively activate PAR-4. PAR-4 plays a significant role in various physiological and pathological processes, particularly in the context of blood coagulation and inflammation. It is widely studied for its involvement in platelet activation, where it contributes to thrombus formation, making it a potential target for antiplatelet therapies in cardiovascular diseases. PAR-4 is also implicated in cancer progression, as its activation can influence tumor growth, metastasis, and angiogenesis, providing a pathway for therapeutic intervention in oncology. Additionally, research explores its role in inflammatory diseases, such as arthritis and sepsis, where modulating PAR-4 activity could help manage excessive inflammation. Its unique mechanism of activation by proteolytic cleavage makes it a promising target for developing selective inhibitors or agonists in drug discovery. This high-purity (≥98%) compound, confirmed by NMR and IR spectroscopy, serves as a valuable tool for studying PAR-4 signaling pathways.