Each tube of Neosporin includes an expiration date. Before each use, check the expiration date to make sure it's safe to use. Johnson & Johnson Consumer Companies, the manufacturer of Neosporin, advises throwing away the tube if it has surpassed its printed expiration date.
According to the product label, Neosporin may lose its effectiveness in treating burns, cuts and scrapes after its expiration date. If using this product when close to its expiration date, check the consistency, color and odor. Discard unused Neosporin if it appears chalky or dry, has a tainted color, or has an unpleasant odor, recommends Suzy Cohen, R.Ph., as cited in the Chicago Tribune.