What it is
Ginseng, a slow-growing woodland plant, has been used medicinally for more than 5,000 years. Because the root has long been reputed to increase vitality, ward off degenerative disease, improve memory, and enhance virility, it’s no surprise that its botanical name (Panax) comes from the Latin word panacea, meaning “cure-all.” The two most common types of ginseng used medicinally are Panax ginseng, which grows in Asia, and Panax quinquefolius, or American ginseng, which is native to the cool forests of eastern North America. Siberian ginseng (Eleutherococcus senticosus) is not a true ginseng, despite its common name.

Herbalists refer to ginseng as an adaptogen because it seems to help the body adapt to mental and physical stress. In addition, recent studies indicate ginseng can help regulate blood sugar levels, making it an increasingly popular treatment for insulin resistance syndrome as well as type 2 diabetes.

How it works
Scientists have identified dozens of compounds, including ginsenosides, which they believe to be responsible for ginseng’s beneficial effects. Ginsenosides appear to positively influence hormonal reactions, particularly those related to the stress (or fight-or-flight) response. We’re all exposed to a variety of stress-inducing factors, from cold temperatures to fear, anxiety, and deadlines. Studies show that ginseng helps to lower levels of stress hormones called glucocorticoids, both immediately after stressful incidents and during periods of prolonged stress.

In a 1996 study reported in Phytotherapy Research, 232 subjects suffering from long-term fatigue participated in a double-blind clinical trial. Participants were given a multivitamin/mineral; half were also given 40 mg of a standardized extract of ginseng twice daily. (The rest were given a placebo.) At the end of the trial, only 5.7 percent of ginseng-takers reported fatigue symptoms, compared with 15.2 percent of those taking a placebo.

Side effects
Practitioners of Traditional Chinese Medicine regard American ginseng as milder than Asian ginseng, and more appropriate for long-term use by healthy people under 50. They generally recommend Asian ginseng for use as a vigorous restorative for the elderly and for anyone in a weakened condition. At recommended doses, ginseng rarely causes side effects. (However, Asian ginseng has been known to cause irritability or insomnia in some people.) If you are sensitive to stimulants, avoid using ginseng in combination with caffeine. It may also be prudent to avoid ginseng use during pregnancy and lactation. Diabetics who want to try lowering their blood sugar with American ginseng should start with a low dose and monitor blood sugar as the dose is increased. American ginseng interferes with the clinical effect of the blood-thinning medication warfarin; do not take the two in combination.

How to take it
Ginseng is widely available in a variety of forms. A typical dose of American ginseng is 1 to 4 grams of powdered root daily (generally in capsules) or 1/4 to 1/2 teaspoon daily of liquid extract. Many herbalists suggest using ginseng cyclically—for example, take the herb for one month, and then take a one- to two-month break before resuming. Before using ginseng for blood sugar control, consult a qualified herbalist.