This form of ginseng (one of several) also acts as a powerful antioxidant and has documented anti-cancer activity. It increases immunity against colds and flu and has long been used as an aphrodisiac.

Contraindications to this herb include hypertension or diabetes that is controlled with insulin or oral hypoglycemic drugs. The best-quality extracts are standardized to 1.5 to 7 percent ginsenoside. It appears to have greatest benefit when taken for two to three weeks at a time, with a two-week break in between periods of use.

Cordyceps sinensis
This fungus is a rare find in the wild, harvested in remote areas of China and Tibet at altitudes above 3,500 feet. It is costly - up to $1,000 for 100 grams - and the best varieties are said to come from Tibet. Its adaptogenic and tonic properties make it a mainstay of traditional Chinese herbal medicine.

A 1998 review by Stanford University researchers describes its "oxygen-free radical scavenging, antisenescence, endocrine, hypolipidemic, antiatherosclerotic, and sexual function-restorative activities" in detail. It enhances immune function, stimulating white blood cell production and natural killer (NK) cell activity. Like many other fungi used in Asian medicine, including shiitake and reishi mushrooms, Cordyceps has strong potential as both cancer preventative and cancer treatment. Studies performed at Beijing University in China and in Japan found that it is a highly effective treatment for male impotence (64 percent success rate in the treatment group versus 24 percent in the placebo group).

Extracts should be made from the whole fruiting body of the fungus, standardized to seven percent cordycepin per 500 mg dose. (http://www.chinese-herbs.org/cordyceps/)

Reishi (Ganoderma lucidum)
This fungus was written of in the oldest known Chinese pharmacopoeia, dating back to the first century B.C. Chinese medicine rates it very highly as an overall tonic, a superior medicine that promotes long life and youthful vibrancy. Current research suggests that Reishi is a powerful natural cancer preventative and may be useful for the treatment of some cancers; both cancer and HIV patients seek it out for its immunity-boosting effects, which are thought to derive from its content of beta-glucans and triterpenes. Reishi has also been found to improve blood lipid profiles, aid in controlling both high and low blood pressure, and soothe nervous tension. It has been said to help heal bronchitis, hepatitis, and diminished blood flow to the heart muscle.

Quality supplements are standardized to 10 to 12.5 percent polysaccharides and four percent triterpenes per dose.

Dong Quai (Angelica sinensis)
This herbal medicine, derived from the root of a perennial plant, is widely used in Asia as a female tonic. It has been called "the female ginseng." It is rich in coumarins, plant chemicals that open up blood vessels, improving circulation; coumarins also have relaxant effects on the central nervous system. Some studies suggest that its usefulness for menstrual cramps can be traced back to relaxant effects on the smooth muscles that line the uterus.

In the West, dong quai is most popular as a remedy for hot flashes and other menopausal symptoms. Usually, it is used for this purpose along with other herbs such as black cohosh. It is also used to regulate menstrual cycles, particularly in women who are stopping oral contraceptive use or women who have very heavy periods. In conjunction with chasteberry, it has been found to aid in easing pain from endometriosis.