One-fifth of Ayurvedic medicines made in the United States and India ordered from 25 websites by a team from Boston University School of Medicine and Boston Medical Center were found to have metallic poisons such as lead, mercury or arsenic. About 21 percent of 193 Ayurvedic medicines tested had some or more of the metals. Moreover, half of those exceeded established standards for exposure levels. Some of these herbs are very promising treatments for diabetes, high blood pressure and cholesterol, but the researchers suggested that strictly enforced, government-mandated daily dose limits for toxic metals in all dietary supplements were necessary to ensure safety. They also suggest that all manufacturers should demonstrate compliance through independent third-party testing.