What's Important In Deciding on Sunscreen

Hello, Dr. Samuels. I am very confused about sunscreens. Is the SPF of the sunscreen more important than the ingredients or is there something else I should know about sunscreens? (Marlene Ward)

Marlene, as I’m sure you already understand, ultraviolet rays from the sun or tanning beds are what cause photo-damage to your skin (rough texture, blotchy skin color, brown spots and wrinkles), as well as skin cancer. UVB rays damage the surface of your skin, while the UVA rays are those that penetrate below to damage elastin and collagen, contributing to premature aging from within. No matter what SPF or sunscreen you decide on, I want to emphasize the need for sunscreen application every day. This is where prevention begins.

Let me first mention that screening of UVB rays is done not only by topical sunscreens, but also is aided by the ozone layer and clothing, as well. (For more detailed and interesting information on UVB and UVA protection, watch for my next blog post on Thursday.)

SPF (Sun Protection Factor) is a value given to a sunscreen which indicates its ability to block UVB rays. The higher the SPF, the greater the protection from damaging UVB rays…but not UVA rays. However, it is important to note that an SPF 35 absorbs 97-98% of the UVB rays; and an SPF 50 absorbs 98-99% of the UVB rays. The bottom line becomes that there is not much extra protection beyond an SPF of 35. To this end, there are broad spectrum sunscreens on the market for everyday use that can provide adequate protection.

The sunscreen ingredients that block UVA rays only work for a short time when applied to the skin. However, micronized zinc oxide and titanium dioxide are both stable UVA blockers and have excellent reflective properties to help prevent UVA rays from penetrating and causing damage beneath your skin’s surface.

So the answer to your question, Marlene, is that the SPF and the ingredients are equally important. An effective sunscreen should have an SPF of at least 35 for the face and contain several sunscreen ingredients including zinc oxide or titanium dioxide. Our Facial Moisturizer SPF 35 with transparent zinc oxide, additional sunscreen ingredients, and antioxidants is an example of this type of product.

If you have any other questions about sunscreens or sun damage, please comment below or visit my Facebook page and ask your question there. I will answer it here on my blog as soon as I can.