 Suvorexant is a selective, dual orexin receptor antagonist (DORA) made by Merck & Co.It was approved for sale by the U.S. Food and Drug Administration (FDA) on August 13, 2014.The U.S. Drug Enforcement Administration (DEA) placed it on the list of schedule IV controlled substances, as it may lead to limited physical dependence or psychological dependence relative to the drugs or other substances in schedule IV.