L-Methionine-d4（Cat No.:I043810）is a deuterated form of the amino acid L-methionine, where the hydrogen atoms are replaced by deuterium (d4), a stable isotope of hydrogen. This modification is used in research applications, particularly in metabolic studies, to track the incorporation of L-methionine in biological systems with greater precision using mass spectrometry. L-Methionine-d4 serves as a useful internal standard in isotope labeling experiments, helping to study protein synthesis, amino acid metabolism, and cellular processes. It is also employed in analyzing metabolic pathways and drug metabolism in clinical and pharmaceutical research.