In regards to using sunscreens with different levels of SPFs, Dr. King says: "It's ok to use different SPFs, but keep in mind that improvement over SPF 30 is marginal, and be sure to avoid any skipped areas. If they overlap, the resulting SPF is the higher one at best — it's not a sum of the two, and it's possible that one may dilute the other, resulting in an SPF lower than the higher one."
She says that it's also important to realize that both UVA and UVB rays cause skin cancer, but the SPF actually only tells you about the product's ability to block UVB rays, not UVA rays.
If you want that contoured look, the best and safest thing to do is grab your favorite palette. “Contour with makeup, and protect your skin from damaging UV rays with sunscreen,” says Dr. King. You can use one like Colleen Rothschild Beauty's Triple Defense Sunscreen Broad Spectrum SPF 40, which is a vegan, mineral sunscreen made with zinc oxide and titanium dioxide.
