The effects of Panax ginseng on quality of life.

Panax ginseng is marketed and used to maintain natural energy, increase mental and physical abilities, improve mood and promote general health and well-being. Panax ginseng has been studied in a number of randomized clinical trials investigating its effect on physical and psychomotor performance, cognitive function, immunomodulation, diabetes mellitus and herpes simplex type-II infections. Equivocal results have been demonstrated for many of these indications. P. ginseng is also commonly used to promote quality of life (QoL). As a result, ginseng's effect on QoL has become an increasingly important endpoint in clinical trials. We reviewed all studies (n = 9) that determined the effect of P. ginseng on QoL. P. ginseng's has been evaluated at dosages of 80-400 mg. Study duration has spanned from 2 to 9 months. Several QoL measures have been used, ranging from widely accepted core instruments to unpublished investigator-derived questionnaires. In addition, many of the investigators utilized ginseng extracts that were supplemented with vitamins and minerals while others used only standardized ginseng extract. Populations evaluated also differed in terms of underlying morbidity. Nearly every study evaluated (n = 8) demonstrated some degree of QoL improvement. Beneficial effects were evident within instrument summary component scores but improvement in overall composite scores of QoL was rarely seen. However, findings were equivocal. While populations evaluated varied in terms of underlying morbidity, there did not appear to be a substantial difference in their response to ginseng with respect to QoL. Despite some positive results, improvement in overall health-related quality of life cannot, given the current research, be attributed to P. ginseng. However, the possibility that various facets of QoL may have improved and the potential of early transient effects cannot be discounted.