Source: Fo-ti is the dried or cured root of a twining vine in the knotweed family, found throughout China, except in the extreme northeast. It is also occasionally grown in American gardens as an ornamental. Ask Chinese herbalists about "fo-ti" and they wont know what you're talking about. The name was given to the plant by a marketer in the early 1970s for the American herb business. In China, it is known as he-shou-wu.
In Chinese medicine the dried (unprocessed) root and the cured (processed) root are considered two different herbs. The unprocessed root is used to relax the bowels and detoxify the blood. The processed root is used to strengthen the blood, invigorate the liver and kidneys, and supplement vital energy (qi). Processed fo-ti is one of the more widely used tonics in traditional Chinese medicine (TCM), which employs it to enhance longevity, increase vigor, and promote fertility. It is also an ingredient in TCM formulas for premature gray hair, low back pain, angina pectoris, low energy, and other conditions.
In animals, the processed root reduces blood cholesterol. The root contains lectins, which appear to help prevent cholesterol accumulation in the liver and fat retention in the blood. Animal experiments show it can help reduce formation of plaque and fat deposits on arterial walls. Fo-ti also inhibits the growth of bacteria, increases laboratory animals' ability to adapt to cold temperatures, and promotes the formation of red blood cells. An extract of the processed root has also shown antitumor, antioxidant, and immunostimulant effects in animals. Unprocessed roots lubricate the bowels, producing a laxative effect. Several clinical studies in China suggest the processed herb is useful in treating high cholesterol, heart conditions, and chronic bronchitis. Mounting evidence supports fo-ti's traditional use as a tonic.
The whole root, sliced root, root powder, capsules, tablets, and tinctures are found in the American market, mostly in tonics. Unfortunately, few American herb books (and even the scientific literature) make a distinction between the unprocessed and processed forms of the roots. The processed forms have been boiled in a special black bean liquid according to traditional methods. This "curing" process changes the action of the root. Most American products contain the cheaper unprocessed root, which is mildly laxative. The unprocessed root is light brown to brown in color while the processed or cured root is dark reddish brown.
The unprocessed root can cause loose stools or diarrhea, sometimes with intestinal pain and nausea. The unprocessed root is considered potentially more toxic than the processed form. One case of allergic reaction to the cured root has been reported, although this form of fo-ti is considered to be minimally toxic when taken in proper doses. Large doses have resulted in numbness of the extremities as well as skin rashes.