Can All-Natural Sunscreens Really Prevent Sunburn?

We’re all for reducing your chemical exposure, but can all-natural sunscreens really protect you effectively? The Honest Company controversy raises questions. (Photo: Getty Images/Thomas Barwick)

Since 2012, The Honest Company has successfully carved out its niche as the purveyor of all-natural — yet still beautiful — products (think chevron-print, eco-friendly diapers). Yet the company, which is the brainchild of actress Jessica Alba, has come under fire for its zinc oxide-based sunscreen — a product that’s short on chemicals and short on coverage, according to a vocal group of consumers claiming the SPF 30 product simply doesn’t work.

Experts recommend reapplying sunscreen every two hours. On Amazon.com, one reviewer recently posted that despite diligently reapplying Honest Company sunscreen every two hours, her daughter’s back “looked like a tomato and even blistered in one spot!” Another user compared the product to melted butter — greasy, tough to wash off, and “about as good as [wearing] no sunscreen.” Still another commenter claimed the burn he/she experienced while wearing the product made them feel like they were “out for two hours on a 100-degree day without protection — which makes me believe some of the more natural ingredients and oils in this sunscreen may actually be attracting the sun to the skin.”

A number of Honest Company customers have also taken to Twitter, posting photos of their lobster-like complexions after using the all-natural sunscreen.

And it’s not just lay people who have observed this troublesome trend. “I had a patient who had this problem,” Daniel Wasserman, a dermatologist in Naples, Fla., tells Yahoo Health. But after carefully reviewing the product’s ingredients list, he was left stumped, unable to identify any obvious reasons for the sunscreen’s seeming lack of protection.

The only active ingredient in Honest Company sunscreen is zinc oxide, which is the Environmental Working Group’s first choice for sun protection, because it doesn’t break down when exposed to sunlight and blocks both UVA and UVB rays. Unlike many chemicals found in traditional sunscreens, such as avobenzone, oxybenzone, and ecamsule, which absorb UV rays, zinc oxide protects your complexion by physically blocking the sun’s rays. As Goddess Garden, the maker of an all-natural sunscreen, explains on its website, “[Zinc oxide and titanium dioxide] act like tiny little mirrors that create an invisible shield that bounces the sun’s rays off the skin.”

Another bonus: “Physical blockers,” like zinc oxide and titanium dioxide, “are ideal for people with sensitive skin, because they are unlikely to cause allergic reactions,” notes Rajani Katta, M.D., a professor of dermatology at the Baylor College of Medicine. “Whereas with the chemical sunscreen agents, I actually see allergic reactions to those all the time.”

Although the FDA permits up to 25 percent zinc oxide in sunscreens, an investigation by NBC Chicago revealed that the Honest Company recently decreased the zinc oxide content of its sunscreen from 20 percent to 9.3 percent. “The FDA gives guidelines on what percentage of ingredients you can use, but it’s really left up to the company to decide on the percentages,” says Katta. “[In] most of the formulations that use zinc oxide alone, it’s about 20 percent.”

Earlier this year, when the Honest Company sunscreen still contained 20 percent zinc oxide, the Environmental Working Group named the product a “top choice for sun protection,” citing its “excellent UVA protection” and the low health risk of its ingredients. Yet shortly thereafter, the company reformulated its product, more than halving the amount of sun-blocking zinc oxide it contains.

Related: 3 Tips to Apply Sunscreen the Right Way

Why the decrease in zinc oxide? This ingredient is notoriously chalky (thus the once-ubiquitous white nose of lifeguards) so, according to NBC Chicago, the company opted to cut back on zinc oxide to avoid leaving users’ skin white, and to improve the feel of the sunscreen (reviewers often complain that it’s ultra-thick and greasy).

“The Honest Company has been transparent about the amount of zinc since the new formula came out in early 2015, as seen on the website and the new formula’s packaging,” the company said in a statement to the Today Show. And “when it removed the zinc,” NBC Chicago reports, “the company says it added other ingredients to keep it effective,” although zinc oxide is listed as the product’s only sun-blocking ingredient.

But even a low level of zinc oxide should impart some protection: A 1998 FDA study found that as little as two percent zinc oxide shields against sunburn, although a 25 percent zinc oxide formulation “provides the most protection against sunburning radiation.”

However, “I think you should aim for 10 to 20 percent zinc, especially if it is the only sunscreen ingredient,” says Cybele Fishman, an integrative dermatologist in private practice in Manhattan (who hasn’t personally used Honest sunscreen). “What I don’t understand is how Badger [brand sunscreen] needs 18.75 percent zinc to get an SPF of 30, whereas Honest can get away with only 9 percent zinc and get a 30 [SPF]. Something does not add up.”

Honest is unique in that it only contains one sun-blocking agent. Sunscreens often contain a number of UV protectants, as each ingredient may shield against a different part of the UV spectrum. For example, “some chemicals might block one part of the UVB spectrum really well, but not the other part,” Fishman says. “So you end up having these sunscreens that have four or five chemical blockers in them, because they put them all together to give you adequate broad-spectrum protection.”

As a physical blocker, zinc oxide is a highly effective barrier against both UVA and UVB rays. Problem is, as you lower the percentage of zinc oxide in sunscreen, as the Honest Company recently did, “you’re going to be losing protection,” says Fishman. At a certain point, manufacturers may need to add a chemical blocker to supplement the zinc oxide — for example, Fishman’s favorite sunscreen, EltaMD UV Aero Broad-Spectrum SPF 45, is 9.3 percent zinc oxide, but also contains octinoxate, a chemical blocker that imparts extra UVB protection, without the health risks of some other chemicals, she says.

Related: The Best Sunscreen for Your Face

Plus, the Honest Company sunscreen contains “non-nano” zinc oxide, a larger-particle form of zinc thought by some experts to be safer than the nanoparticle version of the mineral that many sunscreens now use. Because Honest is a health-conscious company, it makes sense that Alba opted for non-nano zinc — but this ingredient is not without its downsides. “The [non-nano zinc oxide] sunscreen is very, very thick, and it’s very hard to rub in,” Fishman tells Yahoo Health. “The reason people are burning may be because they’re can’t actually rub in their sunscreen, so they’re not getting adequate protection.”

The inactive ingredients could also be part of the problem, adds Katta. “If your sunscreen ingredient” — in this case, zinc oxide — “is dispersed evenly, it’s going to work better,” she says. But some inactive ingredients could cause the sun-blocking agent to clump, so you have different concentrations of the ingredient every time you squirt the sunscreen into your palm.

As researchers write in a Dermatologic Therapy article, “The vehicle” — that is, the inactive ingredients — “is equally if not more important than the type and concentrations of the UV filters utilized. … Excess UV filters from a poorly formulated product tend to accumulate in the natural valleys of the skin, leaving poor coverage on the elevations. Uneven coverage results in poor photo-protection.”

The Honest Company specifically says to shake its sunscreen well before using, leading Katta to speculate that uneven distribution of the zinc oxide, due to the product’s formulation, is a concern.

In the Today Show statement, the Honest reps said that the sunscreen underwent third-party testing according to FDA standards, and “the results showed that our product is effective and safe for us as an 80-minute water-resistant (FDA’s highest rating), SPF 30 sunscreen lotion in accordance with FDA regulations when used as directed…The number of complaints received on our own website about our Sunscreen Lotion constitute less than one half of one percent of all units actually sold at honest.com. We stand behind the safety and efficacy of this product.” Yahoo Health reached out to The Honest Company for comment, and received a statement (also published on Honest's blog ) explaining the company's sunscreen testing protocol and desire to address the concerns of customers.

Related: Jessica Alba Speaks Out on ‘Mean Girl’ Moms and Feeling Judged

So could part of the problem simply be that most of us are sunscreen slackers? In a 2013 study of vacationers, published in Photochemical & Photobiological Sciences, researchers found that people failed to apply a thick enough layer of sunscreen, and that over the course of their vacation, they coated less and less of their body, perhaps assuming their tan imparted protection.

“Patients think wearing sunscreen gives them license to bake in the sun for hours,” says Fishman. “That’s completely false. I hear all the time, ‘I don’t understand why I burned. I put sunscreen on!’ But you were out 10 hours. Sunscreen is [a] harm reducer — it doesn’t give you free rein.” That’s true no matter the ingredients in your tube.

Related: Why Your Sunscreen May Not Protect You as Much as You Think

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