Metabolization of deuterated ethanol Although deuterated molecules appear in nature the full deuteration appear only at practically non-detectable level. These molecules are therefore not of endogenous origin. Considering safety deuterium is not radioactive and behaves chemically like regular hydrogene. Despite the metabolic pathway for ethanol degradation being well understood its parameter are not easy to measure. The main reason is that these pathways are also permanently active in other metabolic contexts. Therefore observing deuterated molecules not appearing in nature and their metabolites is a promising method for observation.