Abstract Ipecac ( Psychotria ipecacuanha ) is a perennial, medicinal herb that grows as clusters in the understory of humid, shady areas of the Atlantic Rain Forest of southeastern Brazil. This investigation followed the contents of emetine and cephaeline, the bioactive constituents, and assessed root attributes in roots that were sampled periodically from four clusters of Ipecac (VRB8, ITA1, ITA2, and ITA3) that were growing in natural conditions. HPLC analyses showed that the content of the two alkaloids underwent monthly fluctuations over one year period. The concentration of emetine, but not cephaeline, differed significantly among the four clusters. The highest mean content of emetine was found in VRB8 (1.44%), followed by ITA1 (1.14%), ITA2 (0.63%), and finally ITA3 (0.44%). The highest mean content of cephaeline was found in ITA2 and ITA3 (0.26%), although it was not significantly different from ITA1 and VRB8 contents (0.15%). Correlation analysis revealed that contents of emetine are significant ( P