Griseofulvin represents a rare case of a close-packed organic apohost that can clathrate selected volatile guests in a solid-gas fashion. Inclusion mechanisms and solvent exchange were investigated by a combination of single crystal and powder X-ray diffraction, coupled to optical microscopy and thermal analyses. In particular, gas diffusion and dissolution/recrystallization are alternatively observed, depending on the host polymorph, as well as the chemical nature of the guest and its physical state.