Dermatologist explains how to choose the right sunscreen | Expert Opinion

Countless patients tell me “I used to sunbathe with baby oil and iodine years ago!” Sound familiar? Fortunately, the importance of sun-protective behaviors is more widely known today.

During the pandemic, many of us formed a deeper appreciation for outdoor experiences, which boosted our mental and physical health but also put us at risk for more sun exposure. The good news is that sunscreen allows us to enjoy being outside while preventing skin cancer and aging from UV radiation.

But what kind of sunscreen should you choose? The best sunscreen is the one you will actually use! Look for a few key qualities in sunscreen:

1. Broad spectrum. Broad spectrum labeling means that the sunscreen protects from both UVA and UVB rays. UVB has higher energy and plays a greater role in sunburn and skin cancers. UVA contributes to skin cancers, wrinkles, leathery texture, and premature aging of skin.

2. SPF 30-50. The SPF level indicates how much longer it takes untanned skin to redden from UVB exposure with the sunscreen than without it. For example, it takes your skin 30 times longer to burn wearing SPF 30 compared with no sunscreen at all. While higher numbers do mean more protection, the higher the SPF, the smaller the difference in protection. For example, SPF 30 filters out about 97% of UVB rays compared to 98% with SPF 50. In practice, SPF levels above 50 offer minimal advantage and may mislead consumers into believing they do not need to reapply. No sunscreen can filter out 100% of UVB.

3. Water-resistant (40 or 80 minutes). Although there are no “water-proof” sunscreens, water resistant designations indicate how long the sunscreen remains effective when swimming or sweating. Apply 20 minutes before water exposure to allow the product to absorb into the skin.

Another consideration is chemical versus mineral sunscreens. Zinc oxide and titanium dioxide are typical ingredients in mineral sunscreens, which act as a “shield” by reflecting sunlight away from your skin. Companies now offer “sheer” or “invisible” formulations to minimize the white cast noted with these sunscreens. Mineral sunscreens are preferred for sensitive skin and for infants 6 months and older. Chemical sunscreens rub in easier and do not leave a white residue. These act as a “sponge” and protect our skin by absorbing UV rays.

How you apply sunscreen is just as important as the type. A fairly thick amount is required to get the full benefits of the sunscreen! You should apply about a shot glass-sized amount to the entire body and a quarter teaspoon to the face. If you prefer sprays, I recommend spraying twice. Reapply every hour if active or every two hours if inactive.

My patient who is an avid outdoorsman recently admitted that he and sunscreen have a “casual relationship.” This touches upon the reality that although effective, sunscreen is an imperfect means of protection. People often apply it too thinly, miss areas, or get caught up in activities and neglect to use it. Kids may resist its application at first (keep trying) or apply it imperfectly. Incorporate sunscreen into family and workout routines. Store some in the car, by the doorway, and in your bag. Using SPF in facial moisturizers and makeup enhances consistency.

Sunscreen is best used in combination with other sun-protective behaviors. UPF 50 clothing is more widely available at affordable costs. Seek shade, avoid the strong mid-day UV rays, and wear a hat for added protection.

Elizabeth Jones is an assistant professor in the department of dermatology and cutaneous biology at Jefferson.