However, a recent study of the top consumer-rated sunscreens on Amazon.com discovered that 40 percent of them didn't meet the criteria. The most common reason was that the sunscreen could be washed away by water or sweat.
2. Not using enough
A bottle of sunscreen shouldn't last through the entire summer. The American Academy of Dermatology recommends that you use about an ounce of sunscreen – the amount that could fit in a shot glass – to cover all the exposed areas of your body.
People tend to apply only about a quarter to half of the amount that's needed to provide the maximum amount of protection.
3. Missing some crucial spots
Sunscreen should be used on all exposed areas, so don't forget to apply it on the tops of your ears, the tops of your feet, the back of your hands and on your face, including near your hairline.
And don't neglect your lips, since cumulative exposure to the sun's UV rays can increase your chances of developing lip cancer. A lip-specific product with a sun-protection factor (SPF) of at least 30 should be used.
4. Applying it too late
Don't wait until you're out in the direct sun to start applying your sunscreen. Most sunscreens should be applied about 15 to 30 minutes before you'll be out in the sun, which gives your skin time to absorb them. If you wait until you're out in the sun, your skin isn't protected and could already start to burn.
5. Not reapplying often enough
Don't apply sunscreen once and then forget about it. Even if you're using a waterproof sunscreen, it should be reapplied, at minimum, every two hours, because it starts to degrade over time.
Reapply more often if you're swimming or sweating.
6. Using it only at the beach or pool
If you're going to be exposed to the sun for more than 20 minutes, you should use sunscreen. This not only applies to days at the beach or pool, but also when you're out running errands, walking down the street and driving. This type of exposure adds up over time, and even though you may not receive enough exposure to get burned, you could still be harming your skin.
Sunscreen can help protect your skin against cancer as well as premature aging. Choosing the right product and using it correctly is an easy way to gain substantial benefits with minimal effort and expense.