The lysogenic cycle or lysogeny is one of the two viral reproductive lifecycles (the other one is the lytic cycle) characterized by integrating the viral genome into the host bacterial chromosome. It is also called a non-virulent infection since it does not kill the host.

Lysogeny, or the lysogenic cycle, is one of two cycles of viral reproduction (the lytic cycle being the other). Lysogeny is characterized by integration of the bacteriophage nucleic acid into the host bacterium's genome or formation of a circular replicon in the bacterial cytoplasm.

The lysogenic cycle is a method by which a virus can replicate its DNA using a host cell. Typically, viruses can undergo two types of DNA replication: the lysogenic cycle or the lytic cycle. In the lysogenic cycle, the DNA is only replicated, not translated into proteins.

The lytic cycle involves the reproduction of viruses using a host cell to manufacture more viruses; the viruses then burst out of the cell. The lysogenic cycle involves the incorporation of the viral genome into the host cell genome, infecting it from within.

Bacteriophages have a lytic or lysogenic cycle. The lytic cycle leads to the death of the host, whereas the lysogenic cycle leads to integration of phage into the host genome. Bacteriophages inject DNA into the host cell, whereas animal viruses enter by endocytosis or membrane fusion.