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Quick Dose: How Much SPF Do You Really Need?

Everyone, regardless of age, gender or race, should use sun protection factor (SPF) of 30 or higher. But what’s in your sunscreen may be just as important as the SPF number.

While SPF 85 sounds like it offers more protection, higher SPF numbers can be misleading. The fact is, the higher the SPF, the smaller the difference becomes. SPF 30 blocks 97 percent of the sun rays compared to SPF 50 which blocks 98 percent. Skin cancer doesn’t discriminate. People with darker skin tones need to use sunscreen (SPF 30 or above) as much as people with lighter complexions.

SPF protects you against UVB rays (burning rays), so look for products with broad-spectrum, which protects against both UVA (aging rays) and UVB rays. Choose products that are free of oxybenzone, a compound linked to hormone disruption and cell damage that may lead to skin cancer despite offering effective broad spectrum protection, and retinyl palmitate, a type of vitamin A that may increase your risk of skin cancer, based on reports done on laboratory mice. If you want to avoid potentially toxic ingredients, look for products containing zinc and titanium minerals.

Here are quick tips to protect your family from the sun:

  • Apply sunscreen 15 minutes before going outdoors.
  • Reapply often, or every two hours, and after swimming and sweating.
  • Generously coat your exposed skin with sunscreen, including ears, lips and neck.
  • Most sunscreens expire after three years.
  • The sun’s rays are harmful year-round, and even on cloudy days, up to 80 percent of the sun’s harmful UV rays can penetrate your skin.
Lauren Taglia, MD, PhD, dermatologist, Northwestern Medicine Regional Medical Group