Diabetes advocates are angry over rising insulin costs and calling for greater transparency and federal oversight of the market for a drug that is used by more than 7 million Americans. Three companies—Eli Lilly, Sanofi, and Novo Nordisk—control 99% of the world’s insulin. According to the American Diabetes Association, the average price of insulin nearly tripled between 2002 and 2013. "Americans need Congress to take action to ensure a vibrant, competitive insulin market that serves consumers instead of drug company CEOs. Insulin is not a luxury. It is required for life," said Ben Wakana, executive director of the advocacy group Patients for Affordable Drugs. Reps. Diana DeGette (D-CO) and Tom Reed (R-NY) have been conducting an inquiry into insulin pricing, with the intent of eventually unveiling legislation. Meanwhile, the Senate Aging Committee, chaired by Sen. Susan Collins (R-ME), has also been examining the issue. The American Medical Association recently called for the federal government to protect patients from being harmed by companies' price gouging on insulin products. It wants the Federal Trade Commission and the Justice Department to monitor insulin pricing and market competition and take enforcement actions as appropriate.