Complementary medicine: where is the evidence?

Herbal medicines have been submitted to systematic reviews more frequently than any other complementary therapy, and it is here where the most positive evidence can be found. There is not much research into potential serious risks of complementary medicine. Possible risks range from the toxicity of herbs to vertebral artery dissection or nerve damage after chiropractic manipulation. Currently the Cochrane Library contains 34 systematic reviews of complementary medicine: 20 of herbal medicines, 7 of acupuncture, 3 of homeopathy, 2 of manual therapies, and 2 of other forms.