The aim of this study was to determine whether phagocytic activity and production of cytokines is stimulated by oral application of a commercially available Echinacea preparation. A total of 40 healthy male volunteers (ages 20–40 years) participated in the study. They received either freshly expressed juice of Echinacea purpurea herbs or placebo juice using a double-blind placebo-controlled crossover design with two treatment periods of 14 days and a wash-out period of 4 weeks in between. Endpoints for immune stimulation: phagocytic activity of polymorphonuclear leucocytes and monocytes measured by flow cytometry, production of tumour necrosis factor alpha (TNF)-α and interleukin (IL)-1β by LPS-stimulated blood monocytes. Echinacea purpurea herbs enhanced phagocytic activity neither of polymorphonuclear leucocytes nor of monocytes when compared with placebo. Echinacea purpurea herbs did not influence the production TNF-α or IL-1β by lipopolysaccharide-stimulated monocytes. Unexpectedly, E. purpurea herbs decreased serum ferritin concentration (P = 0.0005). All other laboratory and safety data remained unchanged. Thus, the ‘immune stimulation’ by E. purpurea observed in vitro and after parenteral administration is not confirmed in healthy humans after oral intake.