SPF: Your First Line Of Defense In Skin Care

Updated: May 13, 2021

Here’s your guide to understanding more about those pervasive UV rays and what you can do to level up your daily skin care routine.

Whether you live in a city that has all four seasons or one that lets you flaunt your beach body year-round, one thing remains constant: exposure to the sun’s penetrating UVA and UVB rays. While it might not seem intuitive to apply sunscreen during inclement weather, the reality is that the human body is no match for the sun’s radiation; and unfortunately, the sun can still do a lot damage to your skin in even the harshest conditions. Thankfully, though, there was a God among us who discovered the power of SPF to combat your greatest skin care demons. Fear not, SPF is here to save your skin!

LET'S TALK ABOUT SPF, BABY​ Sun Protection Factor, more commonly known as SPF, is a measure that determines how well a sunscreen will protect your skin from ultraviolet (UV) B rays over a period of time. These rays are the culprit behind your visible sunburn and are able to cause damage to the top layers of your skin. UVB rays are the rays that make a bright sunny day. Furthermore, UVB rays are one of the greatest contributing factors to the development of skin cancers. The intensity of UVB rays varies depending on the time of day and position of the sun. They can also cause even more significant damage to your skin when you are in higher altitudes or in the presence of reflective surfaces, like snow and water. UV rays are strongest between 10am and 4pm. A good way to remember this is by using the use the shadow rule.


Although UVA rays are not factored into the equation for determining a sunscreen’s SPF, they are equally important to discuss. Unlike UVB rays, UVA rays are likely the reason for your sun-kissed tan during the summer (or the one you can get—but should avoid—from a tanning bed). However, the longer wavelengths of UVA rays allow them to penetrate the skin much deeper than UVB rays, making it the worst offender for your skin. UVA rays penetrate into the dermal layer of your skin, VERY DEEP, damaging your precious collagen and elastic. This damage accelerates premature aging, such as developing wrinkles, age spots and loss of elasticity to the skin which causes sagging. While UVB rays fluctuate in strength throughout the day, UVA rays remain consistent during daylight hours all year long. As more research became available about the risks of exposure to UVA rays, broad spectrum sunscreens were developed to provide coverage for both UVA and UVB rays.


If the above hasn’t convinced you yet, then I am here to tell you YES, YES, YES!! Even if you have no sunshine on a cloudy day, UVA rays are still coming through, and strong, the clouds. UVA rays also penetrate through windows, so sunscreen should be worn even when you are staying indoors. Your skin is constantly being exposed to the sun’s powerful UV radiation on a daily basis and broad-spectrum sunscreen can actively diminish the impact of these harmful UV rays on your skin. UVA and UVB rays have damaging effects on everyone, no matter your skin tone. If you won’t take my word for it, here are visible examples of the suns damaging effects on the skin.