In Brazil, a herbal medicinal extract named Catuama containing a mixture of Paullinia cupana (guarana; Sapindaceae), Trichilia catigua (catuaba; Meliaceae), Ptychopetalum olacoides (muirapuama; Olacaceae) and Zingiber officinale (ginger; Zingiberaceae) is used as a body stimulant, energetic, tonic and aphrodisiac. The present study investigated the chronic administration of 25 mL Catuama twice a day during 28 days for any toxic effect on healthy human volunteers of both sexes. No severe adverse reactions or haematological and biochemical changes were reported. Copyright (c) 2005 John Wiley & Sons, Ltd.