The action of ginseng saponins on cell numbers, glucose uptake and lactate production and the activities of specific enzymes associated with glucose oxidation, was tested using a human diploid fibroblast strain. No augmentation of cell numbers was observed. There was a significant increase in the level of cellular lactate levels and in the specific activities of enzymes associated with an anaerobic shift in metabolism. The possible relationship between these findings and the reputed efficacy of ginseng administration in the elderly is discussed.