(±)-Naproxen-d₃（Cat No.:I045073）is a deuterium-labeled form of racemic naproxen, a nonsteroidal anti-inflammatory drug (NSAID) commonly used to treat pain, inflammation, and fever. This compound contains three deuterium atoms, which replace hydrogen atoms, enhancing metabolic stability and enabling precise tracking in pharmacokinetic and bioanalytical studies via mass spectrometry. As a racemic mixture, (±)-Naproxen-d₃ includes both the active (S)-enantiomer and the less active (R)-enantiomer. It is primarily used as an internal standard in drug metabolism research, ensuring accurate quantification and characterization of naproxen in biological samples and pharmaceutical formulations.