The main approaches to the incorporation of tritium and deuterium labels into various classes of biologically active compounds (lipids, nucleotides, amino acids, peptides, low molecular weight bioregulators, etc.) are summarized. The preparation of organic compounds labeled with hydrogen isotopes using various physicochemical methods is described. The effect of reaction conditions on the yield and content of hydrogen isotopes in labeled preparations is considered. Much attention is paid to the incorporation of deuterium and tritium through isotope exchange. Possible mechanisms for the incorporation of hydrogen isotopes and the distribution of the label in organic compounds associated with these processes are demonstrated. It was shown that irradiation of preparations, the use of intermediates, and other innovations can significantly improve the parameters of the desired labeled biologically active compounds.