WASHINGTON -- The Food and Drug Administration warned consumers yesterday not to buy or use the supplements Actra-Rx or Yilishen because they contain an ingredient that could lower blood pressure to unsafe levels. The FDA also moved to block imports of the supplements, calling them "dangerous ... and even life-threatening." The agency said the supplement bears the name Yilishen when it is imported from China and is sold as Actra-Rx within the United States. Laura Alvey, an FDA spokeswoman, declined further comment, saying the matter is under investigation that may lead to criminal or civil enforcement actions. When the FDA...