Expiration dates on many prescription and over-the-counter medications indicate the date on which the potency of the products is no longer guaranteed, according to The Harvard Medical School Family Health Guide. Aside from liquid antibiotics, insulin and nitroglycerin, studies have shown that many antibiotics can last up to a decade.
Pharmacists often place "beyond use" labels on certain medications that direct patients to throw out the remaining medicine by a specific future date, according to Drugs.com. In general, discard dates are approximately one year later than the date on the original manufacturer stock bottle. Expiration dates on medications in the United States are approximately 12 to 60 months following the manufacture dates of the medications.