The characterization of porphyrias as disorders of heme biosynthesis leading to hepatic heme deficiency and raised formation and secretion of heme precursors laid the basis for heme treatment. Although mild attacks sometimes respond to glucose administration, severe attacks or symptoms that are likely to progress should be treated with heme. The heme compounds used in treatment are hematin and heme arginate. In our opinion, heme arginate is preferable to hematin in the treatment of acute porphyrias because of its better stability, fewer side effects, and better documentation of its benefits.