The interaction of any substance with the body is determined by several parameters, namely: its penetration, distribution, transformation and excretion, in other words, ADME properties. Naturally, this fully applies to such a class of compounds as carbon nanostructures (CN). They are mainly formed by sp2-hybridized carbon atoms (with the exception of nanodiamonds formed by sp3-hybridized atoms). However, their properties differ markedly from each other. This review is devoted to examining these differences. This review includes fullerenes, nanoionions, carbon nanotubes, carbon nanohorns, graphene and its derivatives, and nanodiamonds.