Sunscreens 101

I am often asked about what sunscreen to use and what ingredients to look for in a sunscreen. As a Mohs’ skin cancer surgeon, and a cosmetic dermatologist, avoiding the sun’s harmful rays is paramount and critical to any skin care program. 

Of course, avoidance is best but not always practical. Who wants to give up skiing, golf, tennis….or the beach?! For starters, we all should try to minimize our exposure between the hours of 10 am and 4 pm. Hats, sunglasses, umbrellas, and protective clothing should also be important articles in our defense of the sun. And lastly, sunscreen must be used properly.

Proper use of sunscreen starts with the proper cream itself. Inherent in the selection process is knowledge of the proper ingredients. Zinc oxide and titanium dioxide formulations typically block out the whole Ultraviolet A and B spectrums. Zinc oxide was the original white thick paste we used to see lifeguards wear on their noses. There are products with zinc oxide and/or titanium oxide that have become more cosmetically elegant, BUT it can still be difficult to find ones that do not leave at least somewhat of a white film on your skin. 

Consequently, there was a market for chemical sunscreens as opposed to the zinc oxide and titanium dioxide based physical blockers. In the past, it was thought that Ultraviolet B rays were more important and therefore, sunscreens originally typically blocked out the UV-B rays only – with ingredients such as oxybenzone. We then realized that Ultraviolet A rays were just as important if not more important causes of skin cancer and photo-aging. Therefore, in the late 1990’s, sunscreens in the USA evolved to include an ingredient known as Parsol 1789, or avobenzone. So, alas we had UV-A and UV-B protection by combining multiple chemicals and did not require the previously mentioned zinc or titanium based formulations.

But, not so fast, and some of you may be aware that there have been products available overseas with certain ingredients that have been touted to still be superior to those available here in the states. One product that you may be familiar with is Anti-helios, and an ingredient you may have heard of is mexoryl.

If we finally had a chemical UV-A blocker in the form of Parsol 1789, why or how could overseas’ products be better? What we then realized was that when it came to blocking out the UV-A rays, the Parsol 1789 was not very photo-stable; meaning that after approximately 20 minutes of sun exposure, it broke down and was not that effective. While frequent re-application of sunscreen is very important, having to do so every 20 minutes is unrealistic and too inconvenient.

The products overseas contained ingredients such as the mexoryl which was more photo-stable and provided superior UV-A protection. Finally, within the past year or two, in the USA we have cross-linked the UV-A blockers in a manner to provide the same stability as the overseas sunscreen products have. One of the ingredients to look for is called helioplex and Neutrogena, in particular, has several different SPF’s available that contain this ingredient.

So, the choice is to use one of the physical based blockers containing zinc oxide or titanium dioxide or one of the newer based chemical blockers that contain helioplex or something that specifically states that it is cross-linking the UV-A blocker, for the required added photo-stability.

Lastly, patients often ask what number SPF they should use. First of all, SPF only refers to the UV-B protection. If you are going to be outside for extended periods of time, playing a sport, or at the beach…you should use at least a 45 AND do frequent re-applications, especially after sweating or water exposure. If you are just going about your daily errands or commuting to work and are primarily indoors, but getting incidental minimal sun exposure, you should still use a moisturizer or product that contains at least a SPF of 15. 

One anecdote I like to leave patients with is that we all need to keep in mind when the companies come up with their SPF rating, it is all done under exact laboratory conditions. The average person does not put on enough sunscreen and studies have shown that when one puts on a SPF 15, they are actually getting about a SPF 4. For this reason, the higher SPF one applies, the extra margin of protection you will have. 

When will Dr. Kenneth Mark Skin Care have a sunscreen?

We have been doing some research in developing a sunscreen, but again, we want all of our products to be the absolute best. At this time, we feel that the commercially available ones described above are quite good, but we have plans to make ours the best! 


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