Most sunscreens have a three-year shelf life. In these cases, the FDA does not require an expiration date to be printed on sunscreens with long shelf lives. However, in sunscreen products that expire before three years, manufacturers are required to print an expiration date on the label.
After sunscreens expire, the chemicals begin to degrade and separate, making them less effective. Eventually, old sunscreens will crystallize, separate, and may have a foul odor. Always check the expiration date on sunscreen before you purchase it. Keep in mind that extreme temperatures can also make sunscreen become less effective, despite its expiration date.
When in doubt, toss the old sunscreen and buy a new one. If you take good care of your skin, it will take care of you!
Are You Using Enough Sunscreen?When people find bottles of sunscreen around the house, it could mean they aren't using enough during application or applying it daily. Sunscreen should be applied every single day, even in the winter months. Applying sunscreen daily and correctly is the best way to prevent skin cancer and premature aging.
Not using enough sunscreen during application is a common mistake. The rule of thumb is to use about one ounce of sunscreen per adult -- about the size of a shot glass. In the wintertime, you may be more covered up, exposing less skin to the sun's UV rays in the winter, and may not use as much. However, you still need to protect the skin that is exposed, such as hands, face, ears, neck, and if balding, the top of the head.