Dong-quai is the dried root of a member of the parsley family. The plant thrives in high, cool, shaded mountain woods in south and western China. Most of the supply is commercially grown there, rather than wildharvested.
The name dong-quai, or dang-gui, means "proper order". Used in China for thousands of years, it is as highly regarded as ginseng. In traditional Chinese medicine (TCM), the root is believed to nourish the blood and help harmonize vital energy, thus returning the system to proper order. In China it is one of the more frequently prescribed herbs and appears in prescriptions (with other herbs) for abnormal or suppressed menstruation, anemia, and other conditions. In the West, it is used to tone and regulate the female reproductive system and is prescribed for premenstrual syndrome (PMS), menstrual difficulties, and menopause symptoms.
Most research on the plant has been done in China and Japan since the early 1960s. Experiments show that whereas the volatile oil in the root causes relaxation of the uterine muscle, both water and alcohol extracts stimulate uterine contractions; alcohol extracts are stronger. Dongquai also normalizes irregular uterine contractions, improving blood flow to the uterus. The actions do not appear to result from estrogenic activity, as dong-quai does not produce changes in the ovaries or vaginal tissue. It has been shown to improve circulation and lower blood pressure by increasing blood flow in the peripheral vessels and reducing vascular resistance. Experiments have also confirmed that it reduces inflammation, pain, and spasms, and increases the numbers of red blood cells and platelets. Animal studies have also confirmed that dong-quai protects the liver from toxins and helps it to utilize more oxygen. As most clinical studies in China and Japan have involved dong-quai in combination with other herbs, their generally positive results in treating gynecological problems are difficult to assess for dong-quai alone.
Whole dried root, sliced root, powdered root, capsules, tablets, tinctures and combination products are all commonly available in the American market.
Pregnant or nursing women should avoid dong-quai unless under supervision of a qualified medical practitioner. In TCM, it is not given to patients with diarrhea, as it is considered somewhat laxative. Some angelica species are associated with contact dermatitis and related members of the parsley family are known to cause photodermatitis.