The reductive activation of artemisinin (or artemether) by ferroprotoporphyrin-IX, the prosthetic group of hemoglobin, is able to produce covalent adducts heme-artemisinin in high yield under very mild conditions. This adduct formation, using the natural target of an endoperoxide antimalarial drug, confirms the alkylating ability of this class of antimalarial drugs, which has already been reported when using a synthetic manganese porphyrin. (C) Academie des sciences / Editions scientifiques et medicales Elsevier SAS.