But a new study presented at the British Association of Dermatologists (BAD)'s annual meeting found that the SPF in our trusty tube of moisturizer, whatever the factor, might not be offering us the UV protection we think it is.
The study concluded that moisturizers with sun-protection factor (SPF) provide less sun protection than standard sunscreen formulas of equivalent strength; in other words, traditional sunscreens outperformed skin-care and makeup products that have an added dose of SPF.
During the study, researchers from the University of Liverpool enlisted the help of a specially-modified camera that captures UV light in order to look at the ways in which participants applied regular SPF and moisturizers containing SPF — and the results were very different.
After assessing the pictures, researchers found that when an area of skin is covered efficiently by SPF, it appears black under the UV light. When they looked at the pictures of the people who had applied SPF moisturizer, their faces were comparatively lighter, which suggests SPF absorption was less successful and therefore less effective.
"We expected the area of face covered with moisturizer to be greater than sunscreen, in particular the eyelids, because of the perception that moisturizer stings the eyes less than sunscreen," said Austin McCormick, a consultant ophthalmic and oculoplastic surgeon, and one of the study's researchers. "In fact, we found the opposite: the area of the face covered effectively was greater with sunscreen than moisturizer. In addition, where it was applied, the moisturizer provided less UV protection than sunscreen."
"Although skin moisturizer with SPF does provide sun protection, our research suggests that it’s not to the same degree as sunscreen," said McCormick. "We do recommend moisturizers and makeup that contain UV protection, as it's better than no protection at all, but for prolonged periods in the sun we recommend the application of sunscreen with high SPF."
The study also found that people are more likely to miss out certain areas of their face when applying SPF-infused moisturizers — in particular, the eyelids, which BAD says is a huge cause for concern as the lid area is a common site for skin cancers.
In addition, how you apply SPF is important, too, and it seems we aren't slathering on the moisturizer as thoroughly as a regular SPF. In fact, the study concluded that people missed 16% of their face on average, compared to sunscreen at 11%. Matthew Gass, of the British Association of Dermatologists, said: "A good way to prevent this from becoming an issue is to wear sunglasses and reapply sunscreen regularly. This should help protect the bits you miss from being exposed to excessive sun."
Gass concluded, "Unfortunately, moisturizer with SPF just doesn’t perform particularly well in real-world situations compared to sunscreen. Although it may say SPF 30 on the box, this study is just further evidence that lab testing conditions for these products don’t reflect how they are used."
The solution? Invest in a separate SPF to apply over your moisturizer. Sure, it's one more step you'll have to remember in the morning, but it's definitely worth it.