FDA Proposal to Add Bemotrizinol to Sunscreen Monograph

On Dec 11, 2025, the FDA announced a proposed order to add bemotrizinol (also known as Tinosorb S) to the OTC sunscreen monographfda.gov. This proposal – the first new sunscreen active ingredient in decades – is intended to modernize U.S. sunscreen regulation and expand broad-spectrum options. In FDA’s review, bemotrizinol “provides protection against both ultraviolet A and B rays, has low levels of absorption through the skin, and rarely causes skin irritation,” and could be considered generally recognized as safe and effective (GRASE) for adults and children 6 months and olderfda.gov. The agency noted that Americans have long had “fewer options than consumers abroad” and that CARES Act reforms have streamlined monograph updatesfda.govdermatologytimes.com. If finalized, bemotrizinol (at up to 6% concentration as requested by DSM Nutritional Products) will be added to Monograph M020 as a new approved UV filterfda.govdermatologytimes.com.

Bemotrizinol Chemistry and Photoprotection

Bemotrizinol is a large, oil-soluble organic molecule (chemical name bis-ethylhexyloxyphenol methoxyphenyl triazine, C₃₈H₄₉N₃O₅, molar mass ~628 Da) marketed as Tinosorb S or Escalol Sen.wikipedia.orggo.drugbank.com. It is a broad-spectrum UV absorber, with two strong absorption peaks around 310 nm (UVB) and 340 nm (UVA)en.wikipedia.orgcosmeticsdesign.com. Bemotrizinol is highly photostable: even after intense UV exposure it “barely degrades”cosmeticsdesign.com, and it also stabilizes other filters (e.g. protecting avobenzone from photodegradation)en.wikipedia.orgcosmeticsdesign.com. Its high efficacy means that at maximum EU-allowed concentrations it provides one of the highest SPF boosts of any filteren.wikipedia.org.

Mechanistically, bemotrizinol acts like other chemical filters: it absorbs UV photons across the UVB-UVA range and dissipates the energy safely as heat. Because of its large size and lipophilicity, it remains primarily in the stratum corneum and exhibits minimal systemic penetrationfda.govsciencedirect.com. Dermal penetration data from a maximum-use trial showed plasma levels rarely exceeded FDA’s very low threshold (0.5 ng/mL) and there was no evidence of accumulation over timesciencedirect.com. These features – broad UVA/UVA1 coverage, oil solubility, and stability – make bemotrizinol an attractive new filter to fill gaps left by current U.S. actives.

Rationale and Regulatory Context

International use and need. Bemotrizinol has been used in sunscreens in Europe, Asia and Australia for over 20 years, but until now it has not been FDA-approveden.wikipedia.orgstatnews.com. European regulators studied bemotrizinol extensively and permit it up to 10%ewg.org. Dermatologists and public health advocates have long urged the FDA to allow modern EU filters, noting that U.S. sunscreens lag behind global standardsdermatologytimes.comewg.org. For example, the American Academy of Dermatology (AAD) points out that “the United States lags behind many other countries that have nearly twice as many approved sunscreen ingredients”dermatologytimes.comewg.org. Indeed, the EU now authorizes over 30 UV filters in cosmetics, whereas the FDA’s OTC monograph lists only about 15–16dermatologytimes.comewg.org. This limits formulators’ ability to achieve high UVA1 protection and photostability in U.S. products.

Monograph reform. Sunscreens in the U.S. are regulated as OTC drugs, requiring rigorous safety data. Since the last approvals in 1999 (the monograph lists 16 filters, none added since 1999dermatologytimes.com), manufacturers often avoided submitting new data. The CARES Act (2022) reforms have now established a streamlined monograph order process, encouraging companies to petition for new ingredients. DSM submitted an OTC Monograph Order Request for bemotrizinol up to 6%, and FDA’s prompt action reflects the agency’s commitment to modernize sunscreen regulationdermatologytimes.comfda.gov.

Public health impetus. Broad-spectrum sunscreens are a cornerstone of skin cancer prevention. Bemotrizinol’s superior UVA coverage – including UVA1 (340–400 nm) – is particularly important because UVA penetrates deeply and contributes to photoaging, hyperpigmentation, and melanoma riskewg.orgcosmeticsdesign.com. Experts note that consumers and dermatologists have been “denied access to sunscreen ingredients that offer stronger UVA protection”ewg.orgdermatologytimes.com. By adding bemotrizinol, the FDA hopes to give Americans “timely access to the best safe, effective, and consumer-friendly” sunscreen optionsfda.gov.

Safety and Toxicological Profile

Multiple analyses indicate bemotrizinol is safe at the proposed use level. Its large molecular weight and lipophilicity lead to minimal dermal absorption. In maximum-use trials, plasma levels were essentially at background (near the 0.5 ng/mL threshold), with no significant accumulationsciencedirect.com. Systemic exposure is far lower than with older filters like oxybenzone. Topically it shows low skin irritation – FDA notes it “rarely causes skin irritation”fda.gov, and post-marketing surveillance in Europe confirms a low allergy profile. Unlike some organic filters, bemotrizinol exhibits no estrogenic (hormone-like) activity in vitroen.wikipedia.org. Importantly, the clinical trial of 6% bemotrizinol found only one moderate adverse event and a few mild events (e.g. transient redness), but no serious effectssciencedirect.com.

Regulatory agencies have reviewed its safety: the European Commission’s scientific committees deemed bemotrizinol safe for up to 10% use in sunscreensewg.org. U.S. tox studies (as summarized in FDA reviews) showed no genotoxicity or carcinogenic signals. The data package satisfied FDA requirements for an OTC ingredient petition (GRASE review), leading to the proposed order. In short, available toxicology and PK evidence support bemotrizinol’s safety as a sunscreen drug at ≤6%fda.govsciencedirect.com.

Efficacy and Photoprotective Performance

Bemotrizinol’s efficacy stems from its strong UV absorption and stability. With dual peaks (UVB + UVA) it markedly boosts a sunscreen’s broad-spectrum rating. Modeling and formulation studies show that adding 3–6% bemotrizinol can significantly raise a product’s UVA Protection Factor (UVAPF) and SPF by synergistically covering gaps left by avobenzone and othersen.wikipedia.orgcosmeticsdesign.com. In vitro “sun simulator” tests have demonstrated that bemotrizinol even enhances the real-world SPF retention by inhibiting photodegradation of other activesen.wikipedia.orgcosmeticsdesign.com.

Clinically, the FDA-required Maximum-Usage trial confirms that real human use of a 6% bemotrizinol sunscreen did not yield notable systemic absorption, and subjects tolerated it wellsciencedirect.com. There are no large-scale efficacy trials (as SPF labs use standardized methods), but the broad-spectrum protection profile is well documented in the literatureen.wikipedia.orgcosmeticsdesign.com. In practice, dermatologists anticipate that bemotrizinol will allow U.S. sunscreens to achieve higher measured UVA/UVB ratios and more photostable SPF claims. As one expert remarked, “bemotrizinol covers essentially the entire UVB and UVA range”cosmeticsdesign.com, meaning it can meaningfully reduce UVA-driven photoaging and pigmentation.

Comparison with Existing U.S. Sunscreen Actives

Currently, FDA permits about 16 active ingredients (listed in 21 CFR §352.10)fda.gov. These include:

• Mineral filters: Zinc oxide and Titanium dioxide (broad spectrum, very safe).
• Organic filters: Avobenzone (UVA), Oxybenzone (UVA/UVB), Homosalate (UVB), Octocrylene (UVB), Octinoxate (UVB), Octisalate (UVB), Dioxybenzone (UVA), Padimate O and PABA (UVB), Cinoxate, Meradimate, Ensulizole, Sulisobenzone, etcfda.gov.

Most of these are decades-old molecules with limited UVA1 coverage and/or stability. In fact, only zinc oxide and avobenzone currently provide strong UVA protectionewg.org. Nearly all others target UVB or short UVA (330 nm range)fda.govewg.org. Thus U.S. products often depend heavily on avobenzone for UVA, despite its known photoinstability. In contrast, many EU- and Asia-approved filters (bemotrizinol, bisoctrizole, etc.) offer superior UVA1 absorption and photostabilityewg.orgdermatologytimes.com.

Bemotrizinol will complement – not replace – the existing toolbox. For example, adding bemotrizinol to an avobenzone+oxybenzone formula can deepen and broaden UVA coverage and stabilize the SPFcosmeticsdesign.comdermatologytimes.com. Likewise, formulators can use it with minerals: whereas zinc oxide covers UVA well but often leaves texture issues, bemotrizinol allows lighter chemical formulations to achieve the same UVAPF. Overall, bemotrizinol stands out for its broad-spectrum, photostable profile compared to current U.S. actives, addressing long-standing UVA protection gapscosmeticsdesign.comewg.org.

Implications for Pharma and Dermatology

The FDA’s move will have several implications for pharmaceutical and dermatology sectors. Formulators and drug companies now gain a powerful new ingredient to innovate sunscreens. Manufacturers can develop products that meet higher UVA benchmarks (e.g. EU UVA1 criteria) without resorting to old, potentially irritating filters. Dermatologists may welcome new treatment adjuncts: enhanced broad-spectrum sunscreens can improve management of photoaging, melasma, and pigmentation disorders common in darker skin, where UVA1 protection is crucialcosmeticsdesign.comdermatologytimes.com.

From a business perspective, FDA approval opens the U.S. market to formula patents and OTC products containing bemotrizinol. Companies with existing bemotrizinol (Tinosorb S) technology can finally launch U.S. versions of global sunscreens. The CARES Act reforms and this precedent may also encourage filings for other modern filters (e.g. bisoctrizole, ecamsule) that had been pending. Consumer trust in non-mineral sunscreens may rise as new products achieve durable SPF/PA ratings, reducing recent media concerns about mismatched SPF claims. As one dermatologist noted, there has been “a high unmet need for chemical sunscreens that are both broad-spectrum… and safe” – bemotrizinol is hoped to fulfill this need and complement mineral sunscreensdermatologytimes.com.

U.S. vs. Global Regulatory Landscape

The contrast between U.S. and other regions’ sunscreen regulations is stark. In the EU (and Japan/Korea), sunscreens are regulated as cosmetics, allowing rapid introduction of new UV filters with well-established safety dossiers. The EU currently authorizes 34 UV filtersewg.org (and Japan over 20), roughly double the U.S. listdermatologytimes.comewg.org. Many of these were developed in Europe (e.g. bemotrizinol, bisoctrizole, Mexoryl SX/XL) and have been in use for decades. The EU also enforces that the UVA protection be at least 1/3 of the SPF, a standard that FDA only proposed but has not yet mandatedewg.org. Consequently, numerous studies find that typical European sunscreens transmit far less UVA than their American counterparts with the same SPFewg.org.

Asia follows similar practices to Europe. For example, sunscreens in Japan and South Korea routinely contain bemotrizinol for enhanced performancestatnews.com. In fact, a recent analysis notes that “sunscreens available in Japan, South Korea, and E.U. countries have contained bemotrizinol for decades,” with research confirming its topical safetystatnews.com. In contrast, because the U.S. FDA treats sunscreens as OTC drugs, every new filter requires a lengthy approval process. This has historically left American consumers with a subset of globally available technologydermatologytimes.comewg.org. The bemotrizinol proposal is a first step toward closing this gap: its progression through FDA channels suggests that the agency can now consider global sunscreen innovations more nimbly.

Conclusion

The FDA’s proposal to expand the sunscreen monograph to include bemotrizinol has generated broad support from dermatologists and consumer groups. It represents a significant regulatory shift toward modernizing U.S. sun protection. Should the public comment and final review reaffirm the safety/efficacy data, bemotrizinol will be formally added to Monograph M020, giving formulators a potent new tool to enhance UVA and UVB defense. This change is expected to spur innovation in sunscreen formulation, align U.S. offerings with international standards, and ultimately provide Americans with more effective, broad-spectrum options to protect against sunburn, photodamage, and skin cancerfda.govdermatologytimes.com.

Sources: FDA press release and Federal Register noticefda.govdermatologytimes.com; dermatology industry reportsdermatologytimes.comdermatologytimes.com; Regulatory Toxicology & Pharmacology trial datasciencedirect.com; FDA guidance documentsfda.gov; environmental and clinical reviewsewg.orgcosmeticsdesign.com.