Check the Date
The danger of outdated diabetes medicine, says Maria Marcella Sulli, Pharm. D., is that they lose their potency (effectiveness). "They do not degrade into anything toxic," says Sulli, associate clinical professor of pharmacy at St. John's University in Long Island. "But outdated medicine is dangerous if you're relying on it."
Campbell and Sulli agree that expiration dates are fairly generous and are usually not a cause of concern. "The date on the insulin I bought yesterday is 2010 -- more than two years from now," Campbell says. "The chances of me ever needing to use it when it is outdated are really, really, really remote."