Haematin should not be confused with haematein.
Haematin (also known as hematin, ferriheme, hematosin, hydroxyhemin, oxyheme, phenodin, or oxyhemochromogen) is a dark bluish or brownish pigment containing iron in the ferric state, obtained by the oxidation of haem.[1]
Haematin inhibits the synthesis of porphyrin (by repressing ALAS1 synthesis),[2] and stimulates the synthesis of globin. For this reason, it is used in the treatment of porphyrias.
It is a component of cytochromes and peroxidases. Haematin derived synthetically from hemin is used as a reagent.[3]