Sunscreen 101: What You Need to Know


What is the most important skincare product in your skincare arsenal? If you guessed sunscreen, you would be correct. One of the best ways to keep your skin healthy is by wearing a sunscreen every single day – and not just when the sun is shining! 

Applying a sunscreen product with a sun protection factor (SPF) of 30 or more will keep your skin looking young, supple and even-toned. A good sunscreen will protect you against harmful UVA and UVB rays, both of which play a role in the development of skin cancers. 

Keep in mind that not all sunscreens are created equal! It turns out that merely slathering on a product with an SPF is not enough to adequately protect your skin. You must choose the right product, and apply it at the right time and in the right way. It might sound like a lot to think about before you head out the door. But putting some effort into your sunscreen habits now can save you from damaged skin in the future. 

Sunscreen 101: UVA and UVB Rays 

The science behind sunscreen is probably more complicated than you think. To break it down, there are two types of sun rays that can impact your skin. Ultraviolet A (UVA) rays penetrate deep into the skin and contribute to premature aging, wrinkles and skin cancer. You do not feel these rays, but they are present all the time – even on cloudy days and when the sun is not at its peak. 

Ultraviolet B (UVB) rays are the rays that we can see and feel. These rays impact the top layer of the skin and are responsible for producing sunburn. UVB rays contribute to skin cancer even more than UVA rays, and are strongest during the hours of 10:00 a.m. and 4:00 p.m. 

The job of sunscreen is to protect skin from these two types of harmful rays. Sunscreens are rated according to how much UVB protection they provide, known as the sun protection factor. The SPF is a measure of how long you can stay in the sun before getting a sunburn. For example, a sunscreen with an SPF 15 will protect you for about 150 minutes if your unprotected skin normally burns after 10 minutes in the sun (10 minutes times a factor of 15). 

Which Sunscreen Should You Choose?

Many people believe that the higher the SPF, the more protection they get. This is not entirely true. An SPF 30 will block about 97% of UVB rays, while an SPF 50 will block 98% of UVB rays. Only a 1% difference! 

Many dermatologists will recommend wearing an SPF 30 instead of some of the higher SPF products. Why? The higher SPF products give people the illusion of greater UVB protection, so they are more likely to apply less of the product, reapply less often or stay out in the sun longer. 

We have been talking a lot about UVB rays, so you might be wondering how to protect yourself from UVA rays. Most sunscreens are concerned with UVB rays, the ones that give you a sunburn. Because we know more about the harmful impact that UVA rays can have on our skin, many sunscreens now offer broad-spectrum options, which means that they protect from both UVA and UVB rays. 

The sunscreen you choose also depends on what you will be doing. If you are at the beach, swimming in a pool or doing intense exercise, make sure to apply a water-resistant sunscreen. While this does not mean that it will never wash off in water, these products will give you about 40 to 80 minutes of protection while wet. 

Be Sun Smart 

Wearing the right sunscreen product is vital to keeping your skin healthy and younger looking. Staying vigilant on your use of sunscreen, wearing wide-brimmed hats and sun protection clothing and retreating to the shade periodically are all ways you can be sun smart. 

If you have not gotten a skin cancer screening or if you are worried about an abnormal mole, schedule an appointment with Buckhead Dermatology in Atlanta and College Park. Dr. Sherrie Straughn is a board-certified dermatologist with extensive experience in diagnosing and treating a variety of skin conditions for her Atlanta-area patients.