The Chinese herb ginseng is reputed to have many healthful qualities, though rigorous studies tend not to show much effect. But now some studies suggest that ginseng extracts may help combat tiredness that is related to cancer treatments. A randomized double-blind study with 290 cancer patients at the Mayo Clinic in 2010 found that patients taking 1,000 or 2,000 milligrams of ginseng a day reported less tiredness and more energy after eight weeks compared with those given a placebo. In another large study, presented this month to the American Society of Clinical Oncology, the same researchers found that cancer patients given 1,000 milligrams of ginseng twice a day for two weeks saw significant improvements in fatigue compared with a placebo group.
Whether these relatively high doses of ginseng could relieve fatigue in people without cancer—and whether there are any long-term safety issues with such extracts—remains to be determined by further research.