3' deoxycytidine, like hydroxyurea, inhibits DNA synthesis without preventing the initiation of the cell cycle.

3' Deoxycytidine, the cytidine analogue of cordycepin and selective inhibitor of pre-ribosomal RNA in HeLa cells, has been found to be a reversible inhibitor of DNA replication in RNA accumulation. Like other inhibitors of DNA replication such as hydroxyurea, it does not prevent serum-stimulated quiescent 3T3 cells from undergoing the random transition which is rate-limiting for entry into S phase.