Key Takeaways:
What is the best way to make a mineral sunscreen that doesn’t suck? Ask a formulator off the record and you’ll often hear a version of the same answer: You add a sprinkle of ingredients that behave a lot like chemical sunscreens.
Inside labs, the practice has a name: “sunscreen doping,” a term coined by chemical-biomedical engineer Sophie Bai, founder and CEO of Pavise. It’s a tactic that’s surged in recent years as skincare brands chase cast-free, high-number “100% mineral” claims. By functionally “boosting” mineral SPF with chemical sunscreen ingredients, brands get a formula that has the lightweight texture of a chemical sunscreen without having to disclose it on the back of the box.
“SPF boosters are a pretty broad range of ingredients that increase the SPF of the sunscreen … They’re not technically sunscreen actives, so they’re not in the Drug Facts panel,” chemistry PhD and science communicator Dr. Michelle Wong told BeautyMatter. “Some are just solvents that help pigments spread more evenly, some stabilize UV filters, and some essentially act as chemical sunscreens.”
Some so-called “SPF boosters” can act as an emollient to help the product spread better on the skin or help stabilize approved UV filters, but these ingredients don't contribute significantly to the SPF value of the formula. These ingredients may add a slight boost to the approved UV filter performance of the mineral sunscreen ingredients, but not by much. The real gray area is the “doping” ingredients that materially boost SPF, according to Bai.
“By [U.S. Food and Drug Administration] FDA rules, it’s illegal, because they’re not approved UV filters,” Bai told BeautyMatter. “When those [ingredients] are present at fairly high concentrations, you know the function is far beyond cosmetic.”
The FDA regulates sunscreen like an over-the-counter (OTC) drug, and every UV filter must be FDA-approved. The problem is that only a handful actually are. “That’s why you see things like butyloctyl salicylate, tridecyl salicylate and ethyl ferulate—materials structurally similar to approved chemical filters—listed as inactives,” Bai explained. “The FDA doesn’t recognize them as UV filters, but at fairly high concentrations, they essentially behave like UV filters and can add 10 to 30 SPF points.”
Zinc oxide and titanium dioxide are the only sunscreen actives deemed GRASE (generally recognized as safe and effective) in the FDA OTC monograph for sunscreen. Other organic filters need more data, per the FDA’s sunscreen order.
So, how do brands get away with it? As long as an ingredient supplier positions these ingredients as emollients, solvents, or dispersants (aka “inactive” cosmetic ingredients), they can reside outside the Drug Facts panel, even if they influence SPF outcomes.
This classification sits at the heart of the controversy: Can an ingredient truly be inactive if it increases SPF?
Until the FDA adds to its list of approved sunscreen filters, SPF boosters can be classified as inactive ingredients. It’s a legal loophole that brands either knowingly or unknowingly use to make mineral sunscreens look and feel better, but experts say it’s a regulatory gray area with real consumer consequences.
The Rise of SPF Boosters
The rise of sunscreen doping overlaps with something larger: a culture-wide whiplash around sunscreen safety. Social media platforms like TikTok are host to widespread misinformation and conspiracy theories about sunscreen, which medical experts warn is a serious public health threat. At the same time, some brands have seized on distrust to sell alternatives, like Primally Pure, which promoted its new tallow-based sun cream with the tagline, “The sun isn’t poison. Your sunscreen is.”
Misinformation is incredibly effective at changing consumer behavior. Searches for mineral sunscreens have spiked in recent years, increasing by nearly 30% in 2024, with momentum continuing into 2025 and a 35.8% year-over-year surge on Google. Despite its perceived skin health and safety benefits, consumers quickly realized that mineral sunscreens come with their own aesthetic and application drawbacks. Mineral sunscreen tends to leave a white cast on the skin and has a thick texture that can be difficult to spread. Consumers went on the hunt for mineral sunscreens that are cosmetically elegant, which put pressure on brands to develop better mineral sunscreens.
As consumer demand for mineral sunscreens increased, beauty product developers like Tamar Kamen were tasked with creating mineral sunscreens with an SPF 50 and no white cast, which Kamen and other experts say is “impossible” to achieve without nano zinc that would be aesthetically acceptable.
“It’s really hard to find an SPF 50 formula—or anything much higher than an SPF 30—without a booster,” she explained. "With 10% zinc oxide, you can get an SPF 30, but add a booster, and you can achieve an SPF 45 with the same zinc oxide percentage."
Kamen believes the practice is widespread, especially in higher-numbered SPF mineral SKUs. “You could get an SPF 50 [using only zinc and titanium dioxide] with a lot of white cast, but [brands] want to achieve the SPF 50 without the white cast.”
Rising consumer demand for mineral SPF 50 fueled the skincare industry’s wider use of SPF boosters. “Consumers are learning it’s ‘possible’ to have 100% mineral with no white cast … because it’s basically a chemical sunscreen,” said Dr. Wong.
The consumer push for a mineral SPF 50 isn’t entirely grounded in how SPF actually works. While it’s true that a higher SPF number indicates more protection against sunburn-causing UVB rays, the increase in protection is not linear and the difference becomes marginal at higher SPFs. For example, SPF 15 blocks 93% of UVB rays, SPF 30 blocks 97%, and SPF 50 blocks 98%. While higher SPF offers slightly more protection, it does not mean double the protection, and no sunscreen blocks 100% of UV rays. Major health organizations like the American Academy of Dermatology and The Skin Cancer Foundation recommend SPF 30 or higher for daily use.
SPF Boosters: Explained
When added to mineral sunscreen formulations, ingredients like butyloctyl salicylate and tridecyl salicylate can raise measured SPF, improve dispersion, and make zinc and titanium dioxide apply like a dream. Like the old saying goes, if it’s too good to be true, it probably is.
In the US, FDA rules limit the amount of each approved UV filter that can be used. “So if you’re trying to push SPF higher, without increasing the amount of zinc oxide and/or titanium dioxide, you may have to lean on boosters,” explained Dr. Wong.
Because SPF boosters aren’t classified as sunscreen actives, they can appear as “inactive” cosmetic ingredients yet still influence performance, preserving “100% mineral” claims. Actives must be on the Drug Facts panel and are subject to significant safety and manufacturing scrutiny. Inactives are not. If a booster behaves like a UV filter, many experts argue it’s functionally an unapproved active. Yet because these materials aren’t on the approved list, brands can’t legally list them as actives—even if they wanted to.
Butyloctyl salicylate, in particular, is everywhere. “It’s often marketed as an emollient or dispersant, which is true but that’s not why it appears in so many sunscreens,” Dr. Wong said. Depending on the brochure, it’s also described as a material that increases SPF and improves inorganic dispersion. The way it’s sold matters: If marketing downplays UV-active behavior, it can mislead marketers and even some formulators about what an ingredient is really doing in a formula.
Kamen, who often works directly with raw-material vendors, told BeautyMatter that suppliers are explicit about the SPF-boosting effects of these ingredients. “The actives manufacturers 100% sell it as a booster—it’s in their documents,” she said.
But Dr. Wong believes that some manufacturers muddy the waters, marketing the same materials as purely emollients or carriers. “Even when they’re selling it, they’re advertising it in a way that doesn’t tell the full story.” That framing can mislead both beauty brand marketers and even some formulators who may not be aware that their products contain SPF boosters.
The practice of sunscreen doping grew from the convergence of consumer demand and a lag in regulatory oversight. In the US, sunscreen is regulated as an OTC drug, and the FDA’s monograph lists a closed set of approved active UV filters. In 2019, the FDA proposed new rules for sunscreen, stating that most chemical filters required more data to be considered GRASE. Two chemical ingredients, aminobenzoic acid (PABA) and trolamine salicylate, were designated as not GRASE due to safety concerns, while only the mineral filters, zinc oxide and titanium dioxide, maintained GRASE status. The FDA has requested more safety data for 12 other common chemical sunscreen filters.
The Coronavirus Aid, Relief, and Economic Security (CARES) Act, which created a new regulatory process for sunscreens, did not set a deadline for the FDA to issue a final order regarding the chemicals needing further testing. Separately, the FDA is reviewing applications for new ingredients, such as bemotrizinol (marketed as PARSOL Shield and developed by DSM-Firmenich), which is used in Europe and Asia. A ruling on this ingredient could come by early 2026, though this does not affect the status of the ingredients under review from the 2019 proposed order.
Most modern organic (chemical) filters standard in Europe and Asia aren’t approved in the US. Materials like butyloctyl salicylate aren’t recognized as actives, even though their structures and behavior can resemble UV filters used elsewhere. As product developer Tamar Kamen put it, “The ingredients that are the boosters are technically chemical sunscreens that have not been approved by the FDA. So the FDA should also be pretty [annoyed] about it, but right now it’s kosher.”
For Dr. Wong, the practice of sunscreen doping raises questions around safety. “The regulations are there for a reason,” she said. Drug actives are manufactured under strict FDA oversight. Ingredient manufacturing facilities undergo thorough inspections, with validated processes and stringent batch quality controls. “If a booster isn’t a drug active, it won’t face that level of scrutiny,” Dr. Wong explained. “You end up relying far more on the manufacturer’s assurances. It’s a slippery slope.”
Different ingredients within the larger class of SPF boosters carry different safety risks. “Butyloctyl salicylate is very close to octisalate—essentially octisalate with four extra carbons—so from a medicinal chemistry perspective, I’m less concerned there,” said Dr. Wong. “But some other so-called boosters diverge more significantly from the filters they mimic.”
She pointed to ethylhexyl methoxycrylene (similar to octocrylene) as an example where added atoms (like oxygen) can alter how the body processes a compound. “Once you start changing the structure, that changes the ingredient interactions in the body. That’s where safety becomes more of a question mark.”
Mineral, Chemical, or Hybrid?
Most US consumers think they only have two choices: mineral or chemical, but hybrids do exist, according to Dr. Wong. These formulas openly pair mineral actives with approved chemical actives, such as octinoxate or homosalate, like EltaMD’s UV Clear Broad-Spectrum SPF 46. However, mineral sunscreens with boosters aren’t considered hybrid in the regulatory sense because the booster isn’t listed as an active, even if it functionally boosts SPF. That’s why phrases like “100% mineral” are drawing sharper scrutiny from savvy consumers and industry watchdogs. As Kamen put it, if the rest of the ingredient deck implies a chemical assist, “‘100% mineral’ can land you in trouble.”
Consumers who choose mineral sunscreens often do so because they want only mineral actives. Admitting a formula uses a non-approved “booster” to hit SPF 50 could alienate shoppers who only want to use FDA-approved sunscreens.
One way around this, Kamen suggested, is more precise language that calls out “mineral actives” or “mineral sunscreen boosted with [ingredient].” Bai agreed that hybrids can be a sensible option if brands drop scare tactics and label clearly. “People need options,” she said. “For conditions like rosacea or melasma, dermatologists often recommend mineral sunscreen, just because chemical UV filters can worsen inflammation, which could worsen those skin conditions. For others, hybrids or chemical sunscreens are great.”
The Global Picture
Is this just an American story? Yes and no. According to Dr. Wong, the use of boosters is rising globally because expectations have converged: Transparent, weightless, high-SPF sunscreens are now the norm everywhere. Still, the US is uniquely primed for the booster boom. In Europe, Korea, and Australia, brands can choose from a broader toolbox of modern, approved organic UV filters designed for clarity and stability, allowing formulators to hit high UVA/UVB protection without leaning on boosters.
Kamen noted that boosters aren’t as common in places like Korea or Europe because formulators there have access to better chemical UV filters.
“There are a lot of other chemical sunscreens that you can use that have been approved and shown efficacy and safety,” she said. “If you don't like the ones in the US, you can find other chemical sunscreens globally. But if you're looking for a nice mineral sunscreen, you're not going to find new mineral filters anywhere. Your options are the same as they are in the US."
In the US, those newer organic filters aren’t approved. Combine that with heavy pro-clean marketing and the reality that white cast is a deal-breaker across diverse skin tones, and the incentive to rely on boosters skyrockets. The result, Dr. Wong said, is increasingly common everywhere: formulas that are “mineral” by labeling rules but functionally hybrid, fueling confusion for consumers with sensitivities or strict filter preferences.
“It’s a global issue,” she added. “Ingredient companies and sunscreen brands are developing more boosters because demand keeps saying mineral must feel like chemical.”
Pavise’s Patented Mineral UV Filter
Pavise didn’t originally set out to reinvent mineral filters, but that’s where Bai and her team landed after digging into skin aging. “What most people care about—wrinkles, dark spots, texture—traces back largely to sun exposure,” she explains. “And much of that damage comes from UVA, which isn’t what SPF measures.”
Bai argued the industry’s fixation on SPF comes from a testing system that emphasizes UVB protection, which is the basis of SPF numbers. “Because there’s no simple number to chase for UVA from regulations, marketers default to higher SPF,” she said. “But scientists know UVA is a major driver of skin aging.”
That insight shaped the development of Pavise’s patented DiamondCore Shield Technology, a mineral UV filter that goes on sheer, unlike other mineral UV filters. The brand’s Dynamic Age Defense SPF features zinc oxide with a diamond core, ensuring uniform molecular size and shape. This design provides superior broad-spectrum protection by enabling particles to create a more even and robust shield on the skin. Pavise’s patented DiamondCore Shield Technology delivers UVA coverage while also scavenging reactive oxygen species (ROS), which are the free radicals implicated in multiple aging pathways.
“ROS can be generated by UV, stress, and pollution, so we built DiamondCore to address both sides of the problem,” said Bai.
Bai told BeautyMatter that B.A.I. Biosciences, the parent company of Pavise, has invested more than $10 million in molecule and drug discovery, which include a new class of macrosized chemical UV filters—molecules intentionally engineered to be too large to permeate skin, reducing the risk of systemic absorption or accumulation while providing high UVA and UVB protection. She plans to seek FDA approval, but acknowledges the path is slow and costly.
“We’ve spent millions developing new UV filters and manufacturing our own mineral active,” Bai said. “But the timeline and incentives make true innovation hard. We’re between a rock and a hard place because we don’t know how long FDA approval will take.”
The US system, as it currently stands, doesn’t incentivize innovation. The FDA hasn’t approved a new UV filter in roughly two decades, while patent protection typically lasts about 20 years. Researching and developing a new filter, like Bai did, costs millions of dollars and still requires animal testing. “Are we going to do all this research and spend all this money just to become generic as soon as we cross the finish line? Nobody is incentivized to do that. It needs to be a concerted effort among scientists, brands, regulatory bodies, and marketers to bring new UV filters to hundreds of millions of US consumers."
The Future of SPF Boosters
Experts BeautyMatter spoke to for this story agreed that boosters aren’t going anywhere anytime soon. Until the US expands its list of approved sunscreen filters or clarifies how these “inactives” should be classified on the Drug Facts panel, chemists and brands will continue to lean on boosters to hit target SPFs, marketers will keep pushing “mineral” messaging, and consumers will keep buying these “miracle” cast-free mineral formulations and be none the wiser.
Credo Beauty, a clean beauty retailer, doesn’t include SPF boosters like butyloctyl salicylate and tridecyl salicylate on its “Dirty List” of banned ingredients. Christina Ross, Credo Beauty's Head of Science and Impact, told BeautyMatter that the retailer hasn’t excluded them to date because they can play an important role in improving sun protection.
“At this time, with the innovation currently available to the US market, the benefit of enabling effective sun protection outweighs potential concerns around the use of these boosters,” said Ross. “Our focus is on underscoring the importance of daily SPF use, whether mineral or chemical. We are closely following the FDA’s ongoing review of chemical filter safety data, which could open the door to more innovation and safer, more effective SPF options in the US soon.”
Likewise, Sephora’s “Clean at Sephora” seal does not exclude butyloctyl salicylate or tridecyl salicylate, further illustrating that SPF boosters exist in a labeling blind spot, particularly in the “clean” beauty category. The Environmental Working Group (EWG) categorizes butyloctyl salicylate as a low-to-moderate hazard ingredient but with some significant areas of concern. Tridecyl salicylate is rated "low" for common concerns. Products containing butyloctyl salicylate can be approved for the EWG Verified program, but they must meet specific use restrictions and warnings.
Products can earn “clean” badges and even claim “mineral actives” while relying on boosters to cut white cast and hit high SPF numbers. Until policies explicitly address boosters that behave like UV filters, “clean” shelves will continue to include mineral sunscreens that are, functionally, mineral-plus-booster.
Kamen is skeptical that boosters will ever be labeled as actives. Unless the FDA changes course and requires these ingredients to be called what they functionally are, companies have little incentive to seek approval. For now, the status quo keeps the debate alive and keeps mineral sunscreen development balanced between consumer desire and regulatory definitions.
The issue of SPF doping is a microcosm of beauty’s bigger tension: aligning marketing claims, scientific reality, regulation, and what consumers actually want to use. The future likely hinges on balance: Give people elegant protection, describe it honestly, and keep the focus on daily, doable sun safety.
