Toxicity of Echinacea purpurea. Acute, subacute and genotoxicity studies.

Single oral or intravenous doses of the expressed juice of Echinacea purpurea (EP) proved virtually non-toxic to rats and mice. After 4 weeks of oral administration in doses amounting to many times the human therapeutic dose laboratory tests and necropsy findings gave no evidence of any toxic effects in rats. Tests for mutagenicity carried out in microorganisms and mammalian cells in vitro and in mice all gave negative results. In an in vitro carcinogenicity study EP did not produce malignant transformation in hamster embryo cells.