Today’s question was asked via the FutureDerm.com Facebook page:
This may be a dumb question but if I don’t ask I will never know the answer. Are spray sunscreens as long lasting as the lotion type sunscreens? Does the protection last as long? I do know that when one applies the spray on variety one should rub the product into the skin to make sure it is applied evenly, but once it is on does it last as well as the lotion type? Thanks!
-Melinda
Dear Melinda,
Spray sunscreens have the following disadvantages:
- Harder to apply evenly and to cover all parts of the skin, since the formulas go on clear;
- Harder to put on enough product (still should be roughly 1 shot glass full for your face with each application);
- Many contain drying alcohols, which may irritate sensitive skin. (Neutrogena Sheer Mist SPF 45 is my favorite, containing 68% drying SD alcohol 40, whereas other brands, such as Coppertone Sport SPF 30, contain 76% SD alcohol 40.)
There are not many studies comparing the efficacy of spray sunscreen to lotion. However, one interesting mini-study for a university class conducted in 2009 (source) found a higher level of protection with lotion, as lotion allowed only 200 W/m2 of UVB radiation and 150 W/m2 UVA radiation to pass through, whereas spray allowed 400 W/m2 UVB and 320 W/m2 UVA. Would I base professional recommendations on a non peer-reviewed, non-published study like this one? No. But is it well-designed, interesting, and likely to make me personally grab the lotion before the spray off the drugstore shelf? Certainly.
Bottom Line
Given the fact it is more difficult to apply spray sunscreens evenly and in high enough quantity to provide the listed protection on the bottle (2 mg per 1 cm2 of skin), I personally prefer lotion sunscreens. With that said, if you apply the product evenly and in high enough quantity, federal regulations require that the sunscreen provides the listed UVB protection and time of action, typically 3-4 hours.
