SPF100 sunscreen more effectively protects against sunburn compared with SPF50, according to the findings of a recent study published in the Journal of the American Academy of Dermatology.
For their study, the researchers recruited 199 healthy men and women. Participants wore both sunscreens simultaneously on designated treatment areas during an average 6.1 hours of sun exposure. The researchers evaluated erythema the following day and compared the presence of sunburn and erythema scores between treatment areas.
Immediately following sun exposure, 55.3% of participants were more sunburned on the SPF50 side compared with 5% of participants who were more sunburned on the SPF100 side.
At 1 day post-sun exposure, 40.7% of participants had increased erythema scores on the SPF50 side compared with 13.6% of participants on the SPF100 side.
“SPF100+ sunscreen was significantly more effective in protecting against sunburn than SPF50+ sunscreen in actual-use conditions,” the researchers concluded.
Williams JD, Maitra P, Atillasoy E, Wu MM, Farberg AS, Rigel DS. SPF 100+ sunscreen is more protective against sunburn than SPF 50+ in actual-use: Results of a randomized, double-blind, split-face, natural sunlight exposure, clinical trial [published online December 29, 2017]. J Am Acad Dermatol. http://dx.doi.org/10.1016/j.jaad.2017.12.062.