Аннотация:Cryochemistry is a powerful method of micronization and structure changing of organic nanoparticles. In the case of drugs it’s lead to improve pharmacol properties. Cryochemical method of modification based on using of a metastable state obtained by condensation of their vapors on the cooled surface. Low temperature is applied for modification of an analog natural hormone – Δ5-androstendiol-3β,17β. A crystal monohydrate of androstendiol with particle size of 220±10 nm was obtained as a result. Using this method we are able to reduce particle size of organic crystal powder saving molecular structure.