Natural Products

Dong Quai

Angelica polymorpha sinensis, Chinese angelica, Dang qui

Efficacy

• Indications with proven efficacy:
  None
• Indications with proof that it is not effective:
  Symptoms of menopause (when used alone)
• Also used for these other indications, but with no proof of efficacy:
  Anemia
  Analgesic and antispasmodic
  Central nervous system stimulant
  Constipation
  Hypertension
  Menstrual irregularities
  Prevention and treatment of allergic attacks
  Psoriasis
  Rheumatism
  Skin discoloration
  Uterine stimulant

Security

• Risk of Drug Interactions: High
• Adverse Effects: Frequent

What is it?

Dong quai is an aromatic herb commonly used throughout the Orient. The root is used for its medicinal properties. This plant has been used in combination with other herbs for centuries as part of Chinese traditional medicine to treat gynecological ailments such as menstrual cramps or irregularities. There are several proposed used for dong quai: gynecological problems, symptoms of menopause, hypertension, rheumatism, anemia, constipation and many others. In most situations, its efficacy has failed to be established. Coumarin derivatives are extracted from the roots. Some of its constituents have vasodilator and antispasmodic activity. The root also contain psoralens, which are photosensitizing and can cause severe skin reactions upon sun exposure. In addition, these psoralens are mutagenic and carcinogenic.

Warning

In 2004, Canada adopted new regulations that control the manufacturing, packaging, labeling and importing of natural health products. The new regulations also include an adverse reaction reporting system. Products that conform to the regulation's criteria are identified with a natural product number (NPN) or homeopathic medicine number (DIN-HM) and can be legally sold in Canada. This number indicates that the product meets specific criteria for safety and purity, not that it is effective for any indication.

Medicinal plants content varies naturally from plant to plant – just as fruits from the same package may vary in taste and texture. There is no standard to measure the active content of each plant. Thus, efficacy of natural products should be expected to vary from brand to brand as well as from bottle to bottle of the same brand.

For more information about the Natural Health Products Regulations, or to check if a product has been assessed, visit the Health Canada website at http://www.hc-sc.gc.ca/dhp-mps/prodnatur/index-eng.php.

Does it work?

There is no evidence that dong quai is effective in any indication. However it is used to treat many problems where it may be of some benefit:

• Usual doses:
  Recommended dosages variation is important and usually it is used in combination with other herbs. Typically, doses ranging from 3 to 4 grams per day are taken in 3 divided doses with meals. One product supplier suggests doses based on body weight:
  - less than 45 kg = 520 mg, 3 times a day
  - 45 to 80 kg = 1040 mg, 3 times a day
  - over 80 kg = 1560 mg, 3 times a day

Is it safe?

• The risks associated with the use of dong quai are difficult to establish. With normal doses, the product does not appear to be associated with any severe toxicity. Large doses could result in severe skin reaction when exposed to the sun. Even though dong quai is classified as a potentially unsafe drug (carcinogenic and mutagenic potential), it has been used for centuries in Chinese traditional medicine without incidents.
• Most authors agree that dong quai should not be used during pregnancy and breast-feeding.
• Dong quai may potentiate the effects of antiplatelet agents and warfarin (Coumadin™). Before taking dong quai, check with your pharmacist to make sure that there are no interactions with your regular medications.

Clinical notes

• Dong quai has been used in combination with other herbs for centuries in Chinese traditional medicine, mainly to treat gynecological ailments. It may be somewhat effective in some indications. The uncertainty surrounding its safety and the lack of reliable information concerning its safety make it difficult to recommend dong quai in any indications.

References

1. Natural Medicines Comprehensive Database, Therapeutic Research Faculty, 2007
2. Peirce, Andrea. Practical Guide to Natural Medicines, APha, 1999
3. Facts & Comparisons, The Lawrence review of natural products, 1998
4. Chandler, Frank. Herbs – Everyday Reference for Health Professionals, CphA – CMA, 2000
5. Passeportsanté.net. Angélique chinoise. http://www.passeportsante.net
6. Rotblatt M. et Ziment I. Evidence-Based Herbal Medicine, Hanley & Belfus, 2002
7. Taylor J. CE: Phytomedicinals: Uses, precautions, and drug interactions. Drug Topics 2003;1:79