Paula Begoun, the internet’s “cosmetics cop,” hates natural sunscreens, but Gisele Bündchen and a growing (and extremely vocal) number of advocates couldn’t disagree more. In fact, Bündchen famously called the alternative “poison.” Natural sunscreens are certainly a polarizing topic, but why? Should you buy them? And do they actually work? Here’s a handy guide to the most confusing category in sun protection.
What is natural sunscreen, anyway?
Natural sunscreen — which is a name used interchangeably with “mineral sunscreen,” “physical sunscreen,” or just plain “sunblock” — is the oldest, most rudimentary form of sunscreen. It’s defined by its ingredients, which must always include either titanium dioxide, zinc oxide, or both. These ingredients sit on top of your skin and quite literally “block” ultraviolet rays from reaching your skin.
So what makes it “natural?”
Sunscreens fall into one of two categories: Natural and chemical, also known as “synthetic.” Chemical sunscreens are comprised of a different set of ingredients than mineral sunscreens, and they protect your skin in a totally different way. Unlike mineral sunscreens, chemical sunscreens allow ultraviolet rays to penetrate your skin. However, these rays won’t cause damage because they are absorbed by the ingredients in the chemical sunscreen. In other words, think of chemical sunscreens as a super-absorbent ShamWow, and mineral sunscreens as an umbrella. Both can protect you from getting wet, but in different ways.
Not exactly. Once applied, mineral sunscreens instantly protect your skin. Chemical sunscreens, on the hand, need about 20 minutes to absorb into your skin before they can, in turn, absorb UVA/UVB rays. There’s a vanity issue at play, too. Mineral sunscreens tend to make your skin look chalky and ghostlike. Though newer versions are more flattering, they are in the minority. Chemical sunscreens absorb much more easily, and there are even a new crop of chemical sunscreens that are completely translucent.
Why would anyone want to look like a ghost?
It all comes back to ingredients. The FDA has approved 14 chemical active ingredients for sunscreens. Some of these ingredients, like oxybenzone and octinoxate, are considered hormone disruptors, in that they are believed to negatively impact glands that regulate estrogen levels, thyroid activity, and so forth. Sunscreens that contain at least .5 percent oxybenzone in the E.U. must display a warning label, like a pack of cigarettes. Whereas natural-sunscreen ingredients are not associated with hormone disruption.
Okay, that’s a good reason. Anything else?
Oxybenzone and octinoxate are also environmental hazards. Swimmers who wear sunscreens with these ingredients contribute to coral reef “bleaching” and can kill coral ecosystems over time. Just last month, Hawaii passed legislation that will ban oxybenzone and octinoxate sunscreens in 2021.
So does that mean natural sunscreens are safer than chemical sunscreens?
This is where it gets tricky. The studies that suggest chemical-sunscreen ingredients are harmful to humans don’t reflect real-life sunscreen application. For example, a 2001 study that linked oxybenzone to estrogen activity reached its conclusion after rats were fed oxybenzone. Unless you plan to eat a large quantity of sunscreen daily, it’s difficult to use this study to conclude that chemical sunscreens are unhealthy for humans.