Lipoxin A4-d5 is primarily used in biomedical research as a stable isotope-labeled internal standard for the quantification of Lipoxin A4 in biological samples. It plays a critical role in studies focused on inflammation resolution, as Lipoxin A4 is a potent anti-inflammatory and pro-resolving mediator. Researchers utilize Lipoxin A4-d5 in mass spectrometry-based assays to ensure accurate and precise measurements of endogenous Lipoxin A4 levels in tissues, blood, or other fluids. This helps in understanding its role in various inflammatory diseases, such as asthma, arthritis, and cardiovascular disorders. Additionally, it aids in evaluating the efficacy of therapeutic interventions aimed at enhancing the body’s natural resolution pathways.