Homosalate: The UVB Filter Europe Cut Back to Face Products Only

What homosalate is

Homosalate is the name on the label for 3,3,5-trimethylcyclohexyl salicylate, a synthetic salicylate ester also known as homomenthyl salicylate (CAS 118-56-9). The European ingredient database COSMILE Europe describes it as a soluble organic UVB filter that absorbs UVB radiation from approximately 280 to 320 nanometres — the wavelengths that cause sunburn — and converts the absorbed energy to heat in the upper skin layer. Like octinoxate, it covers UVB only: it gives no meaningful UVA protection on its own, so it appears in blends, with a UVA filter such as avobenzone doing the longer-wavelength work. A sunscreen listing homosalate alone, with no UVA filter and no broad-spectrum claim, is not giving complete protection, however high its SPF number looks.

One detail matters for reading the research: homosalate is not a single molecule but a mixture of cis- and trans-isomers, and the mixture varies. In a 2024 toxicokinetics study, Ebert and colleagues found that sunscreens sampled from German, US and Canadian markets contained a fairly constant 87–92% cis-homosalate, contradicting older reports of mixtures with far more of the trans form — and they showed the two isomers behave differently in the body, with the cis form's oral bioavailability about ten times lower than the trans form's. Studies that treat homosalate as one compound, without saying which mixture they used, are therefore harder to compare than they look.

Tip: SPF measures UVB protection only. A product can carry a high SPF from homosalate while offering weak UVA cover, so check for a broad-spectrum claim and for a named UVA filter in the actives list, not just the SPF number on the front.

Why formulators use it

Formulators use homosalate for the same practical reasons they use the other salicylate filters: it is an oil-soluble liquid that blends easily into light, invisible formulas with no white cast, it is inexpensive, and it contributes a solid share of a product's SPF in a blend. It is also genuinely widespread. A market study cited by Ebert and colleagues found homosalate in about 15% of 444 internationally available sunscreen products, with similar usage in adult and children's sunscreens, while a New Zealand study of 95 sunscreens found it in half of them. That prevalence is why the regulatory argument matters: this is a workhorse filter whose limits reshape whole sunscreen ranges, which is also why Europe gave manufacturers a long transition period to reformulate rather than an overnight ban.

Where you will find it

• Chemical sunscreens — lotions, sprays and sticks, where it is usually one of several actives and a main UVB contributor
• Daily SPF moisturisers, primers and foundations — where a small amount of UVB protection is added to a product whose main job is not sun protection, and where, in the EU, it may still lawfully appear under the face-product rule
• Lip balms and lip products with SPF — where it appears at the lower concentrations used for lip products, and where a little of it can also be swallowed
• Leave-on skin and hair products with UV claims — where it protects the product and the surface from light damage as well as the skin

Related: Octinoxate: The UVB Filter Behind the Reef-Sunscreen Bans — the other UVB filter whose European story also turned on absorption and a fresh safety opinion, with a reef ban attached that homosalate does not have.

The concern: absorption, hormones and a shrinking safety margin

The absorption story is the best documented part of the homosalate file, and it starts with the FDA-linked trial that reshaped the whole sunscreen debate. In the randomised trial by Matta and colleagues, published in JAMA in 2020, 48 healthy adults applied commercial sunscreens to 75% of their body surface at 2 mg per square centimetre, once on the first day and four times daily on the following days. Homosalate reached a geometric mean maximum plasma concentration of 23.1 ng/mL from the aerosol spray, 17.9 ng/mL from the nonaerosol spray and 13.9 ng/mL from the pump spray — the highest of the six filters tested after oxybenzone, and roughly 28 to 46 times the FDA's 0.5 ng/mL threshold that triggers further safety testing. The threshold was passed on day one, after a single application, for every active tested. The authors were explicit that these findings do not indicate that people should refrain from using sunscreen. What the numbers establish is systemic exposure under maximal-use conditions, not harm: the threshold is a trigger for more data, and the trial was designed to find the maximum plausible exposure, not a typical beach-day dose.

A smaller, more recent study fills in what happens after an ordinary single application. Ebert and colleagues had four volunteers apply a commercial sunscreen containing 10% homosalate to at least 80% of their bodies under regular-use conditions — the amount they would normally use, not the laboratory maximum — and followed the parent compound and its metabolites in blood and urine. Elimination was delayed and slower than after swallowing the same compound, with terminal elimination half-times of around 24 hours, and the authors' exemplary calculations of intake doses gave margins of safety between 11 and 92 after a single whole-body application, depending on the approach used. That range sits below the 100-fold margin regulators like to see — but it comes with the authors' own caveats: four volunteers, one application, and an exemplary calculation rather than a regulator's formal assessment. The same study's introduction also records that homosalate has been detected in human urine and in breast-milk samples from the general population: the ingredient does not stay on the skin's surface.

The hormone story is thinner, and the honest version of it holds two findings that pull in opposite directions. In laboratory assays, homosalate shows estrogenic activity and anti-androgenic activity: the advocacy database EWG Skin Deep (labelled here as an advocacy source, not a regulator) cites weak endocrine disruption in an androgen-receptor assay and a Danish listing as a possible human disruptor, and COSMILE Europe summarises the position the same way — in vitro studies suggest effects on oestrogen and androgen balance, but the analysed data provide some indications of potential endocrine effects with no solid in vivo evidence, so the level of evidence is insufficient to consider homosalate an endocrine disruptor. Europe's committee, in its 2021 opinion, called the available evidence on endocrine-disrupting properties equivocal and derived no specific endocrine endpoint for its safety assessment. What drove the European cut, according to the 2024 toxicokinetics review, was instead potential reproductive toxicity seen in an OECD 422 oral repeated-dose study — a different, more conventional toxicology signal, at high oral doses in animals, that shrank the calculated safety margin for whole-body use. The distinction matters: Europe did not restrict homosalate because it proved the ingredient disrupts hormones in people. It restricted it because, once the safety margin was recalculated, the old whole-body limit no longer cleared the bar.

The environmental story is the weakest of the three, and it should not be inflated to match the reef headlines of its neighbours. COSMILE Europe notes that homosalate is suspected of polluting surface waters and of endangering aquatic organisms, and Ebert and colleagues record its detection in freshwater, seawater, wastewater, sediments and aquatic organisms — but COSMILE also states that it is rapidly biodegradable and does not accumulate in fish, which cuts against the "forever chemical" framing sometimes applied to it. Unlike oxybenzone and octinoxate, homosalate is not named in Hawaii's sunscreen sale ban. The environmental case for avoiding it is a precautionary one about a widely used chemical reaching waterways, not a demonstrated reef-bleaching case, and this article does not pretend otherwise.

Related: Oxybenzone: The Sunscreen Filter People Question, and What Replaced It — the filter with the largest absorption numbers in the same FDA trial, and the one Australia's review paired with homosalate for tighter controls.

What regulators and reviewers say

Europe's story comes in three dated steps, and the dates are the point. In June 2021, the Scientific Committee on Consumer Safety (SCCS), asked whether homosalate was safe as a UV filter at up to 10%, answered no — and said it was safe up to 0.5% in the finished product across all product types. In December 2021, asked a narrower question, the committee advised that homosalate is safe as a UV filter at concentrations up to 7.34% in face cream and pump spray. Commission Regulation (EU) 2022/2195 then wrote that narrower permission into law: homosalate is now permitted in the EU only in face products, excluding propellant sprays, at a maximum of 7.34%, replacing the old 10% all-products limit. Non-compliant products could no longer be placed on the EU market from 1 January 2025, and could no longer be made available from 1 July 2025. The practical consequence is blunt: a body sunscreen sold in the EU today should not contain homosalate at all, while a face cream may contain up to 7.34% — and a traveller who buys the "same" sunscreen on two continents may be buying two different formulas.

The United States has not followed. The FDA's 2019 proposed rule for over-the-counter sunscreens put homosalate, with eleven other chemical filters, in Category III — the public record did not contain sufficient data to support a positive generally-recognised-as-safe-and-effective (GRASE) determination at that time — and that proposal was never finalised, so the older maximum of 15% stands and homosalate remains one of the most common actives in American sunscreens. The FDA's own position, repeated with the absorption trials, is that the proposal was a request for more data, not a conclusion that the ingredients are unsafe — but seven years on, the data request is still the operative American position, and the gap between the American 15% and the European face-only 7.34% is the single largest transatlantic split among the common UV filters.

Australia, which regulates sunscreens as therapeutic goods rather than cosmetics, landed in 2025 between the two positions — closer to Europe's. The Therapeutic Goods Administration's safety review of seven active sunscreen ingredients found five of them low risk at their current concentrations, and recommended regulatory controls for exactly two: homosalate and oxybenzone. The review's logic is the same margin-of-safety arithmetic Europe used. A margin of safety of 100 or more is considered satisfactory for long-term use; at the maximum permitted concentration on the whole body, homosalate (like oxybenzone) fell below 100, while limiting use to the face and hands brought it back above 100, at homosalate concentrations between 11.4% and 2.7% depending on the product type and directions. The TGA added the same hormone caveat as Europe: the available information on homosalate and the other filters indicates potential endocrine effects, but the data are not adequate to derive a conclusion about causality in humans — and it listed its own limitations plainly, including that it depended on published assessment reports rather than raw study data, and that it did not consider consumer products other than sunscreens. The advocacy database EWG Skin Deep (labelled here as an advocacy source) sits on the cautious side of the same evidence: it records weak endocrine disruption, a penetration-enhancer finding from a herbicide study, and absorption into skin from the Matta trial, and its product listings treat homosalate-containing products as higher hazard. EWG's profile is a hazard ranking, not a regulator's risk assessment, and the difference between those two things — hazard in a dish versus risk at a real dose — is the whole debate in miniature.

The debate

The position this site takes follows the regulators rather than the slogans: homosalate at sunscreen concentrations is not shown to harm people, the safety-margin case against whole-body use at the old limits is real and has now been accepted by two regulators, and the hormone case is genuinely unresolved rather than secretly settled. If you use sunscreen heavily, over the whole body, every day, the European and Australian reasoning applies most directly to you — and mineral sunscreen answers the question outright. If you use a chemical sunscreen, the more useful questions are whether it is broad-spectrum, whether you apply enough of it, and whether you reapply it — not whether one ingredient on its label appears in a headline.

Who should avoid it, or ask first

• People who use sunscreen heavily, over the whole body, every day — the exact worst-case exposure both the European and Australian assessments modelled, and the use pattern where the safety margin fell short
• People who layer several SPF products daily — face cream, foundation, lip product and body sunscreen together are the pattern the face-only logic is really about, even though no regulator has published a combined-products limit; as a preference, fewer chemical filters across the routine is the conservative choice
• People who prefer a filter with no systemic absorption question — mineral actives sit on the skin's surface, so the Matta absorption numbers simply do not arise
• Parents choosing sunscreen for children who are covered head to toe daily — neither Europe nor Australia has issued a child-specific warning on homosalate, so this is a preference for the best-evidenced option, not a regulator warning; mineral is the usual conservative default all the same
• Anyone who wants the European standard wherever they live — an American or Australian sunscreen at 15% is a different product from a European face product at 7.34%, and the label percentage, where it is printed, is the only way to tell them apart

How to spot homosalate on a label

• Homosalate — the name on US Drug Facts panels, where it appears as an active ingredient with its percentage, up to 15%
• Homosalate — the same name in ingredient lists in Europe, Australia and most of the world, where no percentage is printed and its position in the list hints at the amount
• Homomenthyl salicylate — a synonym for the same compound, still seen on some labels and in older literature
• 3,3,5-trimethylcyclohexyl salicylate — the chemical name, seen in regulatory documents and safety assessments rather than on packs
• The EU face-versus-body trap — a European face cream may lawfully contain homosalate up to 7.34%, while a European body sunscreen should not contain it at all under the current rules; "bought in Europe" is not the same as "homosalate-free"
• Its usual companions — avobenzone (the UVA partner), octocrylene, octisalate and octinoxate (fellow UVB filters in the same blend); a formula that drops homosalate but keeps the rest has narrowed, not removed, the chemical-filter question

Alternatives: the same sun protection, without this filter

The simplest alternative removes the entire debate rather than one ingredient from it: a mineral sunscreen whose only active ingredients are zinc oxide and/or titanium dioxide. Mineral filters scatter and absorb UV on the skin's surface, they carry the strongest regulatory safety standing of any sunscreen actives, and they avoid both the absorption question and the transatlantic limit split. The honest trade-offs are the ones our sunscreen guide works through: a possible white cast, especially on deeper skin tones, a heavier feel than a chemical lotion, and the need to apply generously, since a thin, invisible layer of mineral sunscreen protects far less than its label SPF promises.

Two practical notes close the loop. First, switching filters does not switch off the rest of sunscreen discipline: broad-spectrum cover, enough product (the trials used 2 mg per square centimetre, roughly a shot glass for the whole body), and reapplication at least every two hours, and after swimming or sweating, matter more than which approved filter you chose. Second, as with every free-from claim elsewhere on this site, a product whose only virtue is what it leaves out should still be judged on what it put in instead: a homosalate-free sunscreen with weak UVA cover has not improved your situation by dropping one filter. Read the whole actives list, check the broad-spectrum claim, and let the bottle you will actually reapply be the final judge.

Checked against SCCS Opinion SCCS/1622/20 (2021), SCCS Scientific Advice SCCS/1638/21 (2021), Commission Regulation (EU) 2022/2195, Matta et al. 2020, Ebert et al. 2024, the TGA safety review of seven sunscreen ingredients (2025), COSMILE Europe, and the EWG Skin Deep database (an advocacy source) · Last updated 2026-10-31 · How we assess ingredients

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