Although laboratory experiments suggest it is possible that some substances used in Ayurveda might be developed into effective treatments, there is no scientific evidence that any are effective as currently practiced. Ayurveda medicine is considered pseudoscientific. Other researchers consider it a protoscience, or trans-science system instead. In a 2008 study, close to 21% of Ayurveda U.S. and Indian-manufactured patent medicines sold through the Internet were found to contain toxic levels of heavy metals, specifically lead, mercury, and arsenic. The public health implications of such metallic contaminants in India are unknown.