Putrescine (sometimes spelled putrescin or putrescene) is an organic chemical compound NH2(CHH2)4NH2 (1,4-diaminobutane or butanediamine) formed by and having the smell of rotting flesh.

It is related to cadaverine; both are produced by the breakdown of amino acids in living and dead organisms.

Other foul-smelling chemical compounds include methyl mercaptan and butyric acid.

Note that putrescine is synthesized by healthy living cells by the action of ornithine decarboxylase. The polyamines, of which putrescine is one of the simplest, appear to be growth factors necessary for cell division.