The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.
Avoid in people with a known allergy or sensitivity to dong quai, its parts, or members of the Apiaceae or Umbelliferae families, including anise, caraway, carrot, celery, dill, and parsley. Skin rashes, possible due to an allergic reaction, have been reported with the use of dong quai. An asthma response has occurred after inhaling dong quai powder.
Side Effects and Warnings
Like all Chinese herbs, different quality dong quai exists, and lower-quality dong quai may be contaminated with heavy metals, prescription drugs, or other undesirable substances. There is a risk of dangerous side effects when herbal preparations are mixed together or when taken with prescription drugs. Liquid preparations of dong quai may contain alcohol.
Dong quai may cause low or increased blood pressure. Caution is advised in people taking drugs, herbs, or supplements that affect blood pressure.
Dong quai may increase the risk of bleeding. Caution is advised in people with bleeding disorders or those taking drugs, herbs, or supplements that may increase the risk of bleeding. Dosing adjustments may be necessary.
Dong quai may affect blood sugar levels. Caution is advised in people with diabetes or hypoglycemia, and in those taking drugs, herbs, or supplements that affect blood sugar. Blood glucose levels may need to be monitored by a qualified healthcare professional, including a pharmacist. Medication adjustments may be necessary.
Drowsiness or sedation may occur. Use caution if driving or operating heavy machinery.
Use cautiously in children or people with alcohol dependence or intolerance, anemia, breathing problems, cancer, heart problems, liver disease, sensitive skin, or stomach or intestinal distress.
Avoid using dong quai in people with acute viral infections such as a cold or the flu, hemorrhagic disease (a bleeding disorder), hypermenorrhea (abnormally heavy menstruation), or scheduled surgical or major dental procedures.
Avoid prolonged exposure to sunlight or other sources of UV light while taking dong quai, due to potential photosensitivity. Taking dong quai in combination with tretinoin or St. John's wort may increase sun sensitivity. Avoid suntan oils with high concentrations of dong quai (greater than one percent), due to the theoretical risk of cancer after long-term use.
Avoid in women with hormone-sensitive conditions (including breast, uterine, endometrial, and ovarian cancer), endometriosis or uterine fibroids, thromboembolic disease, or stroke, or those using hormone replacement therapy or oral contraceptives.
Avoid during pregnancy, due to its uterine-stimulant effects, relaxant effects, and anticoagulant properties in humans and animals. Dong quai may increase the risk of miscarriage. Avoid in breastfeeding mothers, because information on its safety is lacking and it may have estrogenic effects.
Use cautiously in people taking agents affected by alcohol, agents for heart conditions, or oral contraceptives.
Dong quai may cause anemia, anorexia, asthma, bloating, burping, cancer, chills, diarrhea, dizziness, dry mouth, sexual hyperfunction (excessive sexual function), fever, gynecomastia (male breast enlargement), headache, hot flushes, impaired breathing, increased heart rate, increased premenstrual syndrome (PMS) symptoms, insomnia, irregular heart rhythms, irritability, kidney failure, laxative effect, loss of appetite, mild tiredness, nausea, pain, photosensitivity (sensitivity to light), reduced or increased menstrual flow, skin cancer, skin rash, stomach distress, sweating, thickening of the lining of the uterus, upset stomach, vaginal bleeding, vomiting, weakness, and wheezing.
Pregnancy and Breastfeeding
The American Herbal Products Association classified dong quai as a Class 2b/2d herb, which is not to be used during pregnancy, unless directed to by an expert trained to use the herb. Canadian regulations require a bilingual label warning on dong quai products against their use during pregnancy.
Avoid using dong quai during pregnancy, due to its uterine-stimulant, relaxant, and anticoagulant properties in humans and animals. Dong quai may increase the risk of miscarriage. Also, many tinctures contain high levels of alcohol and should be avoided during pregnancy.
There is currently a lack of scientific evidence on the use of dong quai during breastfeeding. Nursing mothers should avoid using dong quai.