Dong quai is a perennial herb found in moist areas of southwestern China, primarily in the Szechuan province. A member of the celery family, the plant has a hollow fluted stem reaching as high as two meters. It has pinnate leaves with sharply toothed, ovate leaflets. The plant flowers from May to August, bearing an umbel of greenish-white flowers. The root of the plant, which is divided into several rootlets, is used for health purposes.
In traditional Chinese medicine, dong quai has been valued for centuries as a female tonic, commonly used as the feminine counterpart to the masculine tonic, ginseng. Traditional Chinese herbalists often prescribe dong quai to help regulate menstruation and promote healthy circulation and intestinal health. Millions of Asian women use dong quai to promote reproductive function before, during, and after pregnancy.
The active constituents in dong quai are a group of coumarin derivatives including oxypeucedanin, osthole, imperatorin, psoralen, and bergaptin.
Dong quai is commonly used to treat menopausal symptoms and menstrual complications, due to its purported estrogenic effects, but there is little scientific evidence to support such use. In one trial conducted on 71 postmenopausal women, dong quai produced no estrogen-like effects and was found to be no more effective than placebo in relieving menopausal symptoms. Nevertheless, it is still one of the most routinely prescribed herbs in traditional Chinese medicine, even more widely used than ginseng.
A common dosage recommendation for dong quai is 1 to 2 grams of powdered root, three times per day. Dong quai has low toxicity and appears to be safe at this dosage range. Some compounds in dong quai have phototoxic properties and may cause increased sensitivity to sunlight. Because dong quai has anticoagulant effects, it should not be used by people taking blood-thinning medications, such as warfarin.