GINSENG is becoming increasingly popular in the West, but many of the products on sale are of dubious quality. An analysis of 50 ginseng preparations by researchers in Sweden found that six did not contain ginsenosides - the substances found in the ginseng root, to which most of the herb's effects have been ascribed. In 44 ginseng products the concentration of ginsenosides was less than 10 per cent. A system of quality control is urgently needed for natural remedies, they argue in the Lancet.