What are the possible side effects of Burdock (Arctium lappa)?
Based on traditional use, burdock is generally believed to be safe when taken by mouth in recommended doses for short periods of time. Handling the plant or using preparations on the skin (such as plasters) has occasionally been reported to cause allergic skin reactions. Diuretic effects (increasing urine flow) and estrogen-like effects have been reported with oral burdock use in patients with HIV. Although reports of symptoms such as dry mouth and slow heart rate have been noted in people taking burdock products, it is believed that contamination with belladonna may be responsible for these reactions. Contamination may occur during harvesting. In theory, tannins present in burdock may be toxic, although toxicity has not been reported in animal studies. Tannins can cause stomach upset, and in high concentrations may result in kidney or liver damage. Long-term use of tannins may increase the risk of head and neck cancers, although this has not been seen in humans. Based on animal resear
