HAMP gene encodes Hepcidin protein in humans. Hepcidin is a regulator of iron entry in circulation system in mammals. Hepcidin proteins are observed in high levels in cases of inflammation and leads to decrease in serum iron levels due to trapping of iron within the liver cells and macrophages. Such conditions further lead to anaemia due to unavailability of iron for red blood cell formation. In cases of low Hepcidin levels as in the cases of hemochromatosis and iron overload occurs due to excessive ferroportin mediated influx of iron. Hepcidin exists as preprohormone, prohormone and hormone with 84, 60 and 25 amino acids respectively. Loss of function is resulted due to deletion of 5 N-terminal amino acids. Conversion of prohepcidin to Hepcidin is mediated by convertase furin. Hepcidin contains a hairpin structure which is stabilized by 4 disulphide bonds. In ambient temperatures, it interconverts into two conformations.

Iron metabolism is regulated by Hepcidin. It inhibits transport of iron via binding to iron export channel ferroportin located in the gut enterocytes basolateral surfaces and in plasma membranes of reticuloendothelial cells. Transporter protein are broken by Hepcidin in lysosomes. Ferroportin inhibition prevents iron from being exported along with iron sequestered in cells. Reduction in dietary iron absorption is observed due to ferroportin inhibition which further leads to prevention of enterocytes from allowing iron in hepatic portal system by Hepcidin. Hepcidin increased activity is partly responsible for reduced iron availability observed during chronic inflammation and anaemia. Synthesis and secretion of Hepcidin by liver is controlled by iron stores within macrophages. Many diseases lead to failure in iron absorption and lead to iron deficiency. Beta thalassemia leads to morbidity and mortality, with the main feature of the disorder being excessive iron absorption. Low levels of Hepcidin is associated with iron overload in beta-thalassemia.