PAF C-16-d4 is primarily used in research settings as a deuterated analog of platelet-activating factor (PAF). It serves as an internal standard in mass spectrometry and other analytical techniques to quantify PAF levels in biological samples. This application is crucial for studying PAF's role in inflammatory processes, immune responses, and cellular signaling. Researchers also use it to investigate the mechanisms of PAF in diseases such as asthma, sepsis, and cardiovascular disorders. Its deuterated structure allows for precise tracking and differentiation from endogenous PAF, enhancing the accuracy of experimental results.