If you’ve ever wondered, “How does sunscreen work?” You are not alone. We asked clean cosmetic chemist Kripa Kostline and board-certified dermatologist Rebecca Marcus, MD to explain.
“UV rays signal the skin to replicate the tyrosinase gene,” Coastline said. Tyrosinase is responsible for the first stage of melanin production.
“Sunscreen works by reducing and limiting signals to reduce tyrosinase production,” he explained. Translation: Sunscreen increases the amount of UV radiation needed to damage the skin from the sun.
However, there are differences between the processes behind mineral and chemical formulas. “Chemical sunscreens absorb ultraviolet radiation and catalyze a chemical reaction that converts these rays into heat, which is then released from the skin,” Marcus explained.
Conversely, mineral sunscreens create a sun-blocking barrier. “Physical sunscreens deflect UV rays and physically block UV radiation from reaching the skin,” he continued.
At the moment, zinc oxide and titanium dioxide (common components of the mineral SPF) are the only two ingredients that the Environmental Working Group found safe to use and effective in protecting the skin from UV damage.
If you want to know more, we have already covered the differences between mineral and chemical sunscreen.