- Ryan Harris, MD
How to Choose the Right Sunscreen this Summer
It's that time of year again when everyone heads outdoors to enjoy the warm weather and sunshine. This also means that I get asked several times a day "What sunscreen should I use?" This is a great question and shows that patients do understand that sunscreen is an important part of their outdoor activities. Studies have clearly shown that sunscreen reduces the risk of skin cancer. It has the added benefit of reducing the aging process through prevention of wrinkles, thinning of the skin, and skin discoloration associated with sun exposure.
The first thing I tell patients is that people rarely get a sunburn because they didn't pick the right sunscreen. When they get a sunburn, it is usually from not applying their sunscreen correctly. Most people both fail to apply enough sunscreen to start out, and fail to reapply as often as needed. Studies have shown that people only get about 40% of the sun protection advertised with a typical application. It isn't because the sunscreens don't work, it's because people aren't applying a thick enough layer. In order to cover your entire body, an average person needs about a shot glass full (1oz) of sunscreen. Anything less and you are compromising the effectiveness of your sunscreen. You might be saving some money by trying to stretch your bottle of sunscreen longer, but in the long run it just isn't worth it.
How often do I need to apply?
Unfortunately there is no such thing as all day sunscreen. If you look closely on any bottle of sunscreen, you will notice that any labeled water resistance will not exceed 80 minutes. This means you will need to re-apply your sunscreen at least every two hours if you are outside and sweating or swimming. This can be very difficult. Trust me, I have 5 kids and know how hard it can be to have to constantly reapply to all those bodies. The only thing I have found to work well is to set a timer and once it goes off, everyone decides if they are staying out and reapplying or going into the shade for the rest of the day.
What SPF do I need?
SPF stands for sun protection factor. The number on the bottle corresponds to the amount of harmful ultraviolet rays that are blocked after proper application. A sunscreen with an SPF of 30 will block about 97% of the UV rays from the sun. A sunscreen with an SPF of 50 will block about 98%. As you can see that is not a huge difference, so using a sunscreen of at least SPF of 30 is fine IF you apply it properly. By using one with a higher SPF, it does provide a little more wiggle room for inadequate application. So if you have the choice, choose the higher number.
I've heard that chemicals in sunscreen are dangerous. Should I still use one?
This is a great question. First off, let's discuss the two main types of sunscreen: chemical and physical. A chemical sunscreen has ingredients that actually absorb the UV rays and prevent them from passing into the skin. You can think of them like a sponge for UV rays. They are the most common type of sunscreen and have the advantage of rubbing easily into the skin. A physical sunscreen actually causes the UV rays to bounce off the skin kind of like a mirror reflecting light. These sunscreens contain the minerals zinc oxide and/or titanium dioxide. They work well but have the disadvantage of not rubbing in completely which leaves a visible white residue on the skin.
Studies have shown that our bodies absorb some of the ingredients in chemical sunscreens. Just because they are absorbed, it doesn't mean these sunscreens are dangerous. The FDA has asked manufacturers to do more research to find out if the low levels of chemicals absorbed lead to any negative health consequences. We are still waiting on the data from those studies, but for now we have no reason to believe that chemical sunscreens are dangerous.
That being said, I completely respect the desire to avoid chemicals if a person has any questions about their safety. Also, some people may be allergic to the chemicals in sunscreen and would benefit from avoiding a chemical sunscreen. In that case, people should rely primarily on sun protective clothing, hats, umbrellas, and use a physical sunscreen to any exposed skin. Personally, I mostly use chemical sunscreens. I wear sun protective clothing so I only need to apply sunscreen to a few areas. If I am getting exposed to chemicals, my exposure is very limited. For my kids, I rely on sun protective clothing for their first line defense. For exposed skin, I try to use physical sunscreens, but I don't feel bad if I use a chemical sunscreen if that is all I have.
What should I look for on the bottle?
As we already discussed, you should purchase a sunscreen with an SPF of at least 30. Your sunscreen should also say that it has broad spectrum UVA and UVB coverage. This means that it will block all the harmful UV rays. If you are going to be sweating or swimming, you should find one that states it has 80 minutes of water resistance. If you are worried about exposure to chemicals, choose one that only has the active ingredients of titanium dioxide or zinc oxide.
Are sunscreen sprays or sticks ok?
Even amongst my dermatology colleagues, there are differing opinions on sprays. Personally, I have used them on myself and kids and never had an issue. When I see someone applying a spray on a windy day, I worry that more is blowing off into the wind than is getting on their skin. Other than that, I have no issue with sprays.
My wife and I love the sunscreen deodorant-type sticks for our kids. It is so hard to get them to sit still and let us apply anything. They fight us no matter what we use, but they fight us less if we offer to use the stick, so we try to always have one of those on hand.
What are my favorite brands?
Admittedly, I am not very picky and tend to buy whatever is on sale at Costco. I have never had a sunburn regardless of the brand I chose as long as I applied it correctly. I tend to purchase Neutrogena as I like the way their products feel on my skin and they have always done a good job protecting my skin. My favorite is the Neutrogena Ultra Sheer Dry-Touch Sunscreen. I have competed in a 200 mile one-day bicycle race called Lotoja three times, and even won it in 2019. During this race, riders barely have time to go to the bathroom, so stopping to reapply sunscreen is unfortunately out of the question for those hoping to win. While I do not recommend this, I have managed to avoid getting even a slight sunburn during my 9+ hour ride by applying 2-3 coats of the Neutrogena Ultra Sheer before the start of the race. Again, this is not how sunscreens are intended to be used, but it does show how incredibly effective they can be if applied liberally.
For the face, my favorite sunscreens are Epionce Daily Shield Tinted SPF 50 or Elta MD UV Clear SPF 46. They both contain a physical sunscreen and are tinted to prevent any white residue. They can be worn alone or under makeup.
I haven't been good at using sunscreen, should I be worried?
Although most people do not end up getting skin cancer, about 1 in 5 people will eventually develop one. Around 14,000 people will die from the various forms of skin cancer each year in our country. These numbers are a little scary and will hopefully motivate you to use good sun protection habits and monitor yourself for skin cancer.
So go ahead and have a great time outdoors this summer, but don't forget to pack your sunscreen!
For more information on the need for skin cancer screening and what signs to look for to detect a skin cancer, click on the following links to other helpful pages on our website:
Do I Need to See a Dermatologist for Skin Cancer Screening?
Basal Cell Carcinoma Information
Squamous Cell Carcinoma Information