The deuteration process implies the exchange of hydrogen (1H) in the structure of various compounds for an atom of deuterium (2H), a stable, non-radioactive hydrogen isotope. The incorporation of deuterium atoms into drug molecules can change the properties of absorption, distribution, metabolism and excretion of that drug. Deuterated compounds often show improved pharmacokinetic profiles and lower toxicity while retaining their pharmacodynamic properties. Given that C–D bonds are stronger than C–H bonds, H/D exchange can significantly slow down the metabolism of compounds, and thus increase the bioavailability of drugs. Deuterated terminal alkynes are particularly important because they are the precursors of a number of deuterated molecules. For many years, scientists have been trying to develop a simple, selective, economical and environmentally friendly method of isotopic exchange. This work is aimed at the development of a simple protocol that would enable the deuteration of terminal alkynes in a relatively short time, with a high incorporation of 2H isotopes, by applying mild reaction conditions without the use of catalysts. With this aim, the H/D exchange of 1,1-dimethyl-propargyl alcohol was successfully carried out in heavy water as a deuterium donor and in the solvent mixture DMSO-d6-D2O (φ(DMSO-d6) = 6.78%) at room temperature, in a relatively short time, with high isotope incorporation (>99%). It was also measured that the addition of DMSO to D2O slightly slows down the H/D exchange reaction, i.e. increases the Gibbs activation energy. All results were obtained using NMR spectroscopy, and they provide a good basis for continuing research on the deuteration reaction of various compounds, including drugs, which have terminal alkynes in their structure, with the use of D2O and the solvent mixture DMSO-D2O or the mixture of heavy water with other organic solvents.