History of aspirin other studies from the 1960s to the 1980s established aspirin's efficacy as an anti-clotting agent that reduces the risk of clotting diseases. Aspirin sales revived considerably in the last decades of the twentieth century, and remain strong in the twenty-first with widespread use as a preventive treatment for heart attacks and strokes. Medicines derived from willow trees and other salicylate-rich plants have been part of pharmacopoeias at least dating back to ancient Sumer. The Ebers Papyrus, an Egyptian medical text from ca. 1543 BCE, mentions use of willow and myrtle (another salicylate-rich plant) to treat fever and pain. Willow bark
History of aspirin fever-reducing properties gave many sick patients enough strength to fight through the infection, and aspirin companies large and small earned the loyalty of doctors and the public—when they could manufacture or purchase enough aspirin to meet demand. Despite this, some people believed that Germans put the Spanish flu bug in Bayer aspirin, causing the pandemic as a war tactic. The U.S. ASA patent expired in 1917, but Sterling owned the "aspirin" trademark, which was the only commonly used term for the drug. In 1920, United Drug Company challenged the "Aspirin" trademark, which became officially generic for public sale in the