We happened to have a packet of zinc oxide powder on hand, so we decided to give it a try. Smith won’t reveal the exact proportions of each ingredient, but we eyeballed the emollients and added a generous amount of zinc oxide powder. Zinc oxide powder is the only one on this list that offers sun protection, says Yolanda C. Holmes, a Washington, DC-based dermatologist and FAAD.
“These ingredients may be good moisturizers for your skin, but they don’t protect you from the sun,” she says, “and they may make you more susceptible to sunburn.”
Holmes doesn’t recommend homemade sunscreens because the ingredients in them can be irritating to some people, and says “sunscreens should be scientifically tested in a lab to make sure they provide a certain level of sun protection.”
Most homemade sunscreens don’t provide effective sun protection, says dermatologist Daniel D. Bennett, treasurer of the American Academy of Dermatology, and they haven’t undergone the rigorous testing that the Food and Drug Administration requires of over-the-counter sunscreens, he says.
The sunscreen was super easy to make: it took less than an hour to mix and another hour to set in the fridge, it went on smooth, smelled fresh and natural, and left as white as most sunscreens.
Once the homemade concoction had set, we compared it to a lab-made sunscreen with SPF 50 using purple UV-detecting stickers. The non-medical circular stickers are applied to the skin and turn clear when a sunscreen with sufficient UV protection has been applied.
I applied the stickers to my hands and arms, and the morning sun quickly disappeared behind the clouds. I then applied some homemade sunscreen to my hands and an SPF 50 product to my arms.
When the sun returned, the sticker underneath the store-bought sunscreen turned clear, but the sticker underneath the homemade sunscreen remained purple.
The sticker packaging says, “If your sunscreen doesn’t turn clear after you apply it, it may be because your SPF is insufficient, your sunscreen is expired, or you didn’t apply enough sunscreen.”
While Holmes said she could not vouch for the science behind the seal, she slammed Smith’s recipe, saying: “The ingredients in this homemade sunscreen do not provide the sun protection you need.”
