The method of preserving a perishable cosmetic and/or pharmaceutical preparation includes adding bioactive glass particles to the preparation, preferably in amounts up to 10 percent by weight. The bioactive glass particles preferably have particle sizes (d50) less than or equal to 10 μm and contain from 40 to 60 wt. % SiO2, 10 to 30 wt. % CaO, 10 to 35 wt. % Na2O, 2 to 8 wt. % P2O5, 0 to 25 wt. % CaF2, 0 to 10 wt. % B2O3, 0 to 8 wt. % K2O and/or 0 to 5 wt. % MgO. A liquid cosmetic preparation with alcohol content insufficient for preservation is preserved in an inconspicuous manner by adding bioactive glass particles with particle sizes less than or equal to 10 μm and with a refractive index close enough to that of the liquid cosmetic preparation so that bioactive glass particles are substantially invisible to an observer.