Research studies.   More than one herb is identified with the term, "ginseng". Asian or Korean ginseng (Panax ginseng) is a perennial herb that grows in northern China, Korea, and Russia. American ginseng (Panax quinquefolius) grows in the central and northern United States and parts of Canada. Siberian ginseng is native to parts of Russia, northern China, Korea, and Japan. Studies with animals reported in The Natural Pharmacy Health Encyclopedia (click Herbs & Supplements , then scroll down to Ginseng) suggest that ginseng increases physical endurance and may help in stress-adaptation. Equivocal outcomes have been evident in studies with humans, with some positive outcomes associated with sports performance and overall physical health and well-being.

Target Symptoms and Dosage.    In this context, the primary target is enhanced physical health and energy. Some have also suggested use of ginseng for problems with erectile dysfunction, but there does not appear to be supportive research evidence. Typical dosage for the Panax ginseng is 100 to 200 mg per day of an extract standardized to contain 4 to 7% ginsenosides. Typical recommendation for Siberian ginseng is a daily dosage of 300 to 400 mg. Many recommend a one to two week "vacation" from this herb after each two to three weeks of use.

Side Effects and Contraindications.   In the recommended amounts, ginseng appears to be generally nontoxic. Side effects of overstimulation and insomnia have been reported, particularly when combined with caffeine. Contraindications for ginseng include high blood pressure and use while pregnant or nursing.

Summary.  For ginseng and other supplements as well, caution is always warranted in combining its use with prescribed medications. The prescribing physician should be involved in any decisions about how or whether to add the ginseng supplement.