Dong quai has been used for over a thousand years as a spice, tonic, and medicine in China, Korea and Japan. Although there have been few definitive studies on dong quai, it is reputed to relieve constipation, increase red blood cell count (which helps treat anemia), and to provide relief from menstrual disorders such as cramps, irregular menstrual cycles, infrequent periods, premenstrual syndrome (PMS), and menopausal symptoms. In Traditional Chinese Medicine, it is used for a variety of purposes, including reproductive, circulatory, and respiratory conditions.

Dong quai grows at high altitudes in the cold, damp, mountain regions of China, Korea and Japan. This fragrant, perennial plant has smooth purplish stems and bears umbrella-shaped clusters of white flowers and winged fruits in July and August. The yellowish-brown thick-branched roots of the dong quai plant have a number of medicinal uses. It takes three years for the plant to reach maturity, after which time the root is harvested and formulated into tablets, powders, and other medicinal forms.

Dong quai contains compounds that, in laboratory tests, have demonstrated activities that may translate into reduction of pain, dilation of blood vessels, and stimulation as well as relaxation of uterine muscles. Animal studies suggest that dong quai may treat abnormal heart rhythm, prevent accumulation of platelets in blood vessels (contributing to plaque formation or atherosclerosis), protect the liver, promote urination, act as a mild laxative, promote sleep, and fight infection.

The scientific evidence regarding the use of dong quai in people is weak. The data consist primarily of laboratory and animal studies as described above, with a few preliminary studies in people. More studies are needed to determine the herb's safety and effectiveness in humans.

Reports and studies of possible uses of dong quai include the following:

• Menopausal symptoms—some women report relief of symptoms such as hot flashes from this medicinal herb; however, clinical studies to date do not support the effectiveness of dong quai for menopausal symptoms.
• PMS—studies suggest that dong quai offers some value when used in conjunction with other Chinese herbs, particularly black cohosh, to treat PMS.
• Anemia—there are individual reports of successful treatment of anemia using dong quai, but to date no studies verify this.
• Heart disease—when used in combination with ginseng (Asian ginseng) and astragalus (Astragalus membranaceus), dong quai decreased symptoms of chest pain and improved exercise tolerance in a small group of people with heart disease.
• Stroke—a series of reports published in China indicate that the use of dong quai just following a stroke demonstrated a decrease in the amount of brain damage; more research is needed.
• High blood pressure—reports indicate that dong quai may lower blood pressure in some individuals.
• Ulcers—animal studies suggest dong quai may soothe ulcers, but studies in people are needed before a definitive conclusion can be drawn.

Other conditions for which dong quai has been used clinically, although studies are still lacking:

• Constipation
• Migraine headache
• Pain
• Liver disorders

In different parts of the world, dong quai is available in a variety of forms including tablets, powders, and injectable solutions. The latter are used in China and Japan in appropriate hospital or health center settings; injectable solutions are not available commercially in the United States or other Western countries and homemade injectable solutions should never be used.

Dong quai should be stored in a cool, dry place and, like all herbal products, be used prior to the expiration date.

Dong quai is not recommended for children because no information relating to appropriate doses of the herb for children has been found in the literature to date.

Dried herb (raw root) may be boiled or soaked in wine before consuming.

Powdered herb (available in capsules)—500 to 600 mg tablets or capsules up to 6 times per day.

Tincture (1:5, 70% alcohol): 40 to 80 drops (equivalent to 2 to 4 mL; there are 5 mL in a teaspoon) 3 times per day.

Drinking the essential oil of dong quai is not recommended because it contains a small amount of cancer-causing substances. The amount of oil in the herb and its extracts is not significant and is not a health concern.

Dong quai should not be used by those who have chronic diarrhea or abdominal bloating.

Dong quai, particularly at high doses, may increase an individual's sensitivity to sunlight and subsequently cause skin inflammation and rashes. People taking dong quai should minimize their exposure to sunlight or use sunscreen while taking the herb.

Dong quai should not be used during pregnancy because it may affect the muscular functioning of the uterus. It should also be avoided by nursing mothers, because there is little information about its effect on the infant through breast milk.

Dong quai should not be given to children because of the lack of information regarding its use in this age group.

Dong quai may interact with the following medications and herbs:

Warfarin
Dong quai can increase the potency and, therefore, potential risks of blood-thinning medications, such as warfarin, so it should not be taken with these medicines.

Hormone medications
Although there is little research on the use of dong quai with hormone medications such as estrogens, progesterones, oral contraceptives, tamoxifen or raloxifene, health practitioners advise against using them together due to the possibility of adverse effects.

Blood-thinning herbs
Although reported extremely rarely and not published in the scientific literature, combining dong quai with other herbs that thin the blood could possibly increase the risk of bleeding in some people. Herbs with such potential that should be used only with tremendous caution and supervision when combined with dong quai include feverfew (Tanecetum parthenium), garlic (Allium sativum), ginger (Zingiber officinale), ginkgo (Ginkgo biloba), ginseng (Asian ginseng), licorice (Glycyrrhiza glabra), chinese skullcap (Scutellaria baicalensis), and turmeric (Curcuma longa).

Herbs or medications that cause sun sensitivity
Given that dong quai may increase an individual's sensitivity to sunlight, it should not be taken with other medications or herbs (such as St. John's wort) that cause the same reactions.

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