The Tincture of "Pau-Pereira" is produced from the stem bark of a plant popularly known as "pau-pereira" and supposed to be Geissospemun vellosii. Analysis by TLC and HPLC showed that Aspidosperma parvifolium, one among several Apocynaceae species popularly known as "pau-pereira", is not an ingredient of the Tincture of "Pau-Pereira" since the alkaloid uleine, a chemical marker for A. parvifolium, was not detected neither in the plant remedy nor in the stem bark used to produce it and indicated as being Geissospermum vellosii.