Cobaltic protoporphyrin IX is a metalloporphyrin and an inducer of heme oxygenase-1 (HO-1) activity. Unlike other metalloporphyrins, cobaltic protoporphyrin IX induces activity of HO-1, the rate-limiting enzyme in heme catabolism, in vitro and in vivo. It also reduces the activity of δ-aminolevulinate synthase, the enzyme that catalyzes the rate-limiting step of heme biosynthesis, as well as decreases the activity of cytochrome P450 (CYP), in rat liver microsomes ex vivo when administered at a dose of 125 µmol/kg. Cobaltic protoporphyrin IX (5 mg/kg) prevents liver injury and increases in the percentage of hepatic apoptotic cells in a mouse model of liver ischemia-reperfusion injury.It increases survival and decreases the number of lung colony forming units (CFUs) in mice infected with Y. pestis at the same dose.Cobaltic protoporphyrin IX has also been used as a catalyst for the electrochemical reduction of carbon dioxide in carbon electrodes.