Four herbs and a substance in broccoli thought to have anticancer properties should be tested for safety under the National Institute of Environmental Health Sciences' National Toxicology Program (NTP), a federal panel has recommended. The five substances were nominated for testing because of their widespread or increasing use by the public despite the existence of relatively little information about their safety.
The four herbs recommended by the federal Interagency Committee for Chemical Evaluation and Coordination are aloe vera (used as a dietary supplement and a component in cosmetics), ginseng (associated with adverse health effects but touted as promoting vigor), kava kava (marketed as a calmative and mood elevator), and milk thistle (promoted for treatment of liver disease).
Stephenson J. Eyeing Herb Safety. JAMA. 1999;282(11):1028. doi:10.1001/jama.282.11.1028-JHA90007-2-1