Deuterium Labelled Compounds refer to molecules where one or more hydrogen atoms have been replaced with deuterium, a stable hydrogen isotope. Deuterium is twice as heavy as hydrogen, making it useful as a tracer for studying metabolic pathways and biological processes. Deuterated drugs are an emerging area in the pharmaceutical industry where hydrogen atoms in drug molecules are exchanged for deuterium.

This substitution allows Deuterium Labelled Compounds to be visually distinguished from the non-labelled parent compound using analytical techniques like mass spectrometry. The added mass of deuterium provides a distinguishable signature. These labelled compounds serve as useful tracers in metabolic and degradation studies. They enable researchers to track the incorporation and breakdown of compounds within biological systems over time. Due to the kinetic isotope effect, compounds containing deuterium may also exhibit altered metabolic properties like an extended half-life compared to the non-labeled compound.