Dong Quai Root
Angelica sinensis, Apiaceae
Dong quai root or tang kuei consists of the roots of the Chinese plant Angelica sinensis, of the family Apiaceae. It is famous in China as a treatment for gynecological ailments, used primarily as a uterine tonic and valued for its mildly sedative, pain-relieving, anti-inflammatoroy, antispasmodic and alterative properties. It has been used traditionally for the treatment of menstrual cramps and associated weakness, irregular menstruation and amenorrhea, as well as being used to provide relief from menopausal symptoms. Dong quai contains coumarins such as osthol which has a stimulating action on the central nervous system, while others including oxypeucedanin and imperatorin, are known to act as vasodilators and antispasmodics.
It is best to take dong quai prior to menstruation and to stop taking it at the onset of menstruation, since coumarins which act as vasodilators can increase the blood flow, leading to heavy menstrual bleeding. Dong quai should not be taken by people who are taking anti-coagulant medications or who are prone to heavy bleeding. It should not be taken if pregnant. Note that large doses of furanocoumarins such as psoralen and bergapten can cause photosensitization in certain individuals which may result in a type of dermatitis if exposed. However one would have to take large doses of dong quai for this to occur. Protective clothing, sunscreen, and sunglasses are advised for people with long- term exposure to furanocoumarins.
“Angelica sinensis information from NPGS/GRIN”. www.ars-grin.gov. http://www.ars-grin.gov/cgi-bin/npgs/html/taxon.pl?406655.
 Zhao KJ, Dong TT, Tu PF, Song ZH, Lo CK, Tsim KW (April 2003). “Molecular genetic and chemical assessment of radix Angelica (Danggui) in China”. J. Agric. Food Chem. 51 (9): 2576–83.
Jia M, Yang TH, Yao XJ, Meng J, Meng JR, Mei QB (February 2007). “[Anti-oxidative effect of Angelica polysaccharide sulphate]” (in Chinese). Zhong Yao Cai 30 (2): 185–8.
 Page RL, Lawrence JD (July 1999). “Potentiation of warfarin by dong quai”. Pharmacotherapy 19 (7): 870–6.
 Hoffmann, David, Medical Herbalism (2003) Healing Arts Press, Rochester, VT, p. 395. ISBN 0-89281-749-6.