Expiration Date The expiration date identifies the time during which the prescription drug may be expected to meet the requirements of the Pharmacopeial monograph, provided it is kept under the prescribed storage conditions. Most medications are potent and safe after the expiration date. The exceptions are insulin, liquid antibiotics and nitro-glycerine. According to the FDA drugs expire on the date they re projected to have lost 10 percent of their potency, which means they are still 90% effective, although the outdated drug is not as effective as the fresh drug. In general, expiry dates are conservative, and consumers can have confidence that drug labeling claims will be accurate up to, and in some cases well beyond, the labelled expiry date. The reality is that we don t store drugs under ideal circumstances. So when absolute certainty is required, stick to drug products that are not expired. When absolutely necessary, expired drugs are probably safe, however, the potency may be compromised. And before you flush or toss those expired drugs, find ways to dispose of them in a way that minimizes the environmental impact and potential for harm.