Is Sunscreen Helpful or Harmful?

Dermatologist Dr. Shari Lipner explains what you need to know about the ingredients in sunscreens.

A woman rubbing sunscreen on her shoulder

With the arrival of summer and people looking forward to enjoying more time outdoors, it’s important to remember to protect your skin from the sun, while also taking the proper precautions to protect yourself from coronavirus.

When it comes to selecting sunscreen, there are a lot of choices: cream, lotions, sticks, sprays, and different ingredients used. There’s a lot to know about sunscreen ingredients, both the potential benefits and dangers. According to a study published in the Journal of the American Medical Association, some chemicals in sunscreen are absorbed into the bloodstream at potentially unsafe levels. (The researchers noted that the small study was preliminary and did not indicate that people “should refrain from the use of sunscreen.”)

The U.S. Food and Drug Administration (FDA) announced last year that it would be taking a closer look at the ingredients in question and their overall safety. Through its proposed rule, the FDA is working with the industry and other parties on what data the FDA believes it needs. To understand what this all means, Health Matters spoke with Dr. Shari Lipner, a dermatologist at NewYork-Presbyterian/Weill Cornell Medical Center, who explains what consumers need to know about sunscreen, its ingredients, and why it’s still important to wear it to prevent skin cancer and protect the skin from damage.

The safety of sunscreen ingredients has been questioned lately. Would you still recommend people use sunscreen?
Yes. Sunscreen plays a key role in protecting our skin from the sun. Sunscreen does three things: It reduces the risk of developing skin cancer, prevents sunburn, and decreases the signs of aging on your skin. We still recommend using a broad-spectrum sunscreen with SPF 30 or higher.

Can you explain the FDA rule and what it means for consumers?
So, the FDA has issued a proposed rule that asks manufacturers to provide more data about the safety of several sunscreen ingredients. There are already two ingredients that are “generally recognized as safe and effective,” or GRASE, and those are titanium dioxide and zinc oxide. But there are 12 other chemicals that need further evaluation in order to determine whether they can be classified as GRASE. The FDA is asking for more information, but certainly based on the data we have now, they still recommend that we use sunscreen.

What are those 12 ingredients?
Those ingredients are cinoxate, dioxybenzone, ensulizole, homosalate, meradimate, octinoxate, octisalate, octocrylene, padimate O, sulisobenzone, oxybenzone, and avobenzone. The FDA is specifically looking at these ingredients in terms of absorption by the skin and the health risk of absorbed chemicals.

One of the ingredients, oxybenzone, has been rumored to be a hormone disruptor. Is this true?
Some studies have been done — mostly in-vitro studies in rats — in which oxybenzone exhibited some estrogen activity. However, in these studies they used an extremely high concentration of oxybenzone, much higher than humans would get. Researchers estimated that it would take 277 years of daily application of a sunscreen containing 6% oxybenzone to obtain a comparable level of exposure in humans. There have been other studies as well. Oxybenzone was applied to the skin of human volunteers, and researchers saw that there were no biologically significant alterations in the reproductive hormones. So at this time, there’s not enough evidence to claim that it’s a hormone disruptor. It has been used safely since 1978.

Portrait of Dr. Shari Lipner

Dr. Shari Lipner

Do young children or pregnant women need to be concerned about these ingredients?
Generally, it is not recommended to use sunscreen on babies younger than 6 months old. The best way to protect them is to keep them out of the sun. But certainly, for young children, pregnant women, people with sensitive skin, or any person who may be nervous about these ingredients, I would recommend a physical sunscreen. Those are sunscreens that contain the two ingredients that the FDA recognizes as safe and effective: titanium dioxide and zinc oxide.

What is the difference between a chemical sunscreen and a physical sunscreen?
A chemical sunscreen works like a sponge. It absorbs the sun’s rays, and that involves some of the ingredients that are being called into question now. Chemical sunscreens are easy to rub into the skin, and they generally do not leave a white residue. Physical sunscreens act like a shield. They sit on the surface of the skin, and they deflect the sun’s rays. They usually leave a white residue.

Are spray sunscreens safe?
Spray sunscreens are a great option because it is very easy to apply a spray, especially on young children. Just be sure you apply it when it’s not windy and that you apply enough. Also, you would not want to apply to the face because there is a question about inhaling some of the toxins from the spray. A cream, lotion, or a sunscreen stick is best for the face.

What should people do to protect their skin?
I always recommend that patients use a sunscreen that is broad-spectrum, meaning it protects against UVA and UVB rays, is water-resistant, and is SPF 30 or higher. I encourage people to reapply every two hours, especially if you are sweating, swimming, or rubbing off sunscreen. I advise my patients to pick a sunscreen that they are going to use every day. So if you like the way a cream feels, use a cream. If you think you are more likely to use a gel or a stick or spray, use that.

But sunscreen is just one part of a big picture. You also want to seek shade. The sun’s rays are strongest between 10 a.m. and 2 p.m. So try to stay in the shade during that time of day. What you wear is important too. Dress to protect yourself from the sun: Wear a lightweight and long-sleeve shirt, pants, wide brim hat, and sunglasses.

Due to the pandemic, people are wearing masks outdoors. Why is it important to remember to apply sunscreen on their face even if it is covered?
First, a mask only covers part of your face leaving the rest of the facial skin exposed to UV rays. Second, depending on the tightness of the weave of the mask, UV light may still penetrate through the mask. Finally, the mask may move out of place. It is difficult to apply sunscreen while you have a mask on, so make sure you apply sunscreen to your whole face, including your nose and ears, indoors and then put on your mask. You should reapply sunscreen every 2 hours or more often if you are sweating or wet.

So in your opinion, are there some sunscreen ingredients that are safer than others?
I do not think so. We have been using these sunscreens for many, many years safely. The FDA is gathering more data, and I think that is helpful. Personally, I would use both the physical and chemical sunscreens. But if anyone is concerned, they can use the physical sunscreens instead.

Learn more about how you can protect your skin this summer and test your skin cancer IQ.

Shari Lipner, M.D., Ph.D., is a board-certified dermatologist at NewYork-Presbyterian/Weill Cornell Medical Center and an associate professor of clinical dermatology at Weill Cornell Medicine. She treats patients with common dermatologic problems of skin, skin cancers, and cosmetic concerns, as well as nail conditions. She has authored more than 80 manuscripts and book chapters on skin conditions and cosmetics, lectures nationwide, and is frequently called upon by the media for her expert opinion.