Dong quai may interact with the following medications and herbs:

Warfarin

Dong quai may increase the potency and, therefore, potential risks of blood-thinning medications, such as warfarin. It should not be taken with these medicines unless you are under the supervision of a doctor.

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 care providers advise against using them together, due to the possibility of adverse effects, unless you are under the supervision of a doctor.

Blood-thinning herbs

Although reported extremely rarely and not published in the scientific literature, the practice of combining dong quai with other herbs that thin the blood could possibly increase the risk of bleeding in some people. The following herbs with this potential when combined with dong quai -- and which should be used only with caution and under the supervision of a doctor include:

• Feverfew ( Tanacetum parthenium )
• Garlic ( Allium sativum )
• Ginger ( Zingiber officinale )
• Ginkgo ( Ginkgo biloba )
• Ginseng ( Panax ginseng )
• Licorice ( Glycyrrhiza glabra )
• Chinese skullcap ( Scutellaria baicalensis )
• Turmeric ( Curcuma longa )

Herbs or medications that cause sun sensitivity

Given that dong quai may increase your sensitivity to sunlight, you should not take it with other medications or herbs, such as St. John's wort ( Hypericum perforatum ), that may cause the same reactions.