Used as a labeled compound in metabolic studies to trace biochemical pathways involving methyl groups. Its isotopic labeling allows researchers to monitor the incorporation and transformation of methylamines in biological systems using techniques like NMR or mass spectrometry. Commonly applied in pharmaceutical research for drug metabolism analysis and in studying neurotransmitter synthesis where methyl group transfer plays a key role. Also utilized in stable isotope labeling for quantitative proteomics and metabolic flux analysis.