It's not uncommon to find multivitamins or individual vitamin supplements that migrated to the back of the cabinet and are now past their expiration date.
Although it may not be dangerous to take expired supplements, they won't be as strong as when you first bought them.
Generally, an expiration date indicates the last date of their highest level of potency.
Pharmaceuticals, on the other hand, are classified as drugs used to cure, treat, or prevent disease.
As such, expiration dates on supplements merely indicate the last day the manufacturer can guarantee a product will be at its highest level of potency as the vast majority of ingredients in supplements degrade and decompose gradually over time.
In terms of vitamins and minerals, it is worth noting that certain products will degrade at a more rapid rate than others.
Therefore, if you find that a tub of chocolate-flavoured whey, for instance, is no longer palatable, you can throw it out, but that does not mean it is bad for your health in any way.
You can extend the shelf life of most supplements by storing them in a cool, dry place.
The FDA does not require that supplements have expiration dates, but most reputable vitamin companies will try to determine when the supplement loses its potency.