Tinosorb S
Tinosorb S (Bemotrizinol): Benefits, FDA Approval & Sunscreen Guide
Tinosorb S (also called bemotrizinol or BEMT) is a sunscreen filter that dissolves into the oily part of a sunscreen and soaks up UVB and the nearer half of UVA. It does two jobs at once: it blocks a wide stretch of UV by itself, and it steadies the other filters in the bottle, especially avobenzone, so the whole product keeps protecting you for the full time you are in the sun.
Its full name is Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine. You will also see it called bemotrizinol, BEMT, or by the trade names Tinosorb S (BASF) and PARSOL Shield (DSM). It has been used in European sunscreens since 2000 and in Indian ones for years. In June 2026 the US Food and Drug Administration approved it, making it the first new sunscreen active ingredient cleared in the United States since 1999.
In short: Tinosorb S (also called bemotrizinol or BEMT) is an oil-soluble UV filter that covers UVB and UVA II, and is one of the best photostabilisers available, keeping fragile filters like avobenzone from breaking down in sunlight. On its own it does not earn a deep UVA (UVA I) claim, because its absorbance falls away past about 343 nm. What it does instead is make avobenzone's UVA I protection possible, since avobenzone needs a stabilising partner to hold up in sunlight at all. Very little of it gets past the top layer of skin, it leaves no white cast, and it shows no hormone-disrupting activity in testing. It gives no protection against visible or blue light, so it cannot prevent melasma. It is allowed up to 10% in Europe, India and Australia, and up to 6% in the United States, where approval took effect on 9 August 2026.
Worth knowing before the marketing starts. The US approval caps bemotrizinol at 6%, while Europe, India and Australia allow up to 10%. So an American sunscreen can legally carry only about half as much of it as an Indian one. And approval is not the same as availability: DSM, the company that filed for it, holds 18 months of exclusivity from 9 August 2026, so American shelves will fill slowly. If you are reading a wave of "new FDA-approved filter" coverage, this is the part most of it leaves out.
At a Glance: Tinosorb S
Attribute | Detail |
INCI name | Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine |
Other names | Bemotrizinol, BEMT, Tinosorb S (BASF trade name), PARSOL Shield (DSM trade name), Escalol S |
CAS number | 187393-00-6 |
Molecular weight | About 628 g/mol (a large molecule, which is why so little gets into skin) |
Type of filter | Organic (chemical) filter, oil soluble, fully dissolved in the formula |
Coverage | UVB (280 to 320 nm) and UVA II (320 to 340 nm) on its own. Not UVA I, not ultra-long UVA I, no blue light, no visible light, no infra-red, no pollution |
Strongest protection at | Around 310 nm (UVB) and 343 nm (UVA II). Absorbance falls away past that, which is why it does not earn a UVA I claim by itself |
Physical form | Light yellow powder, dissolved into the oil part of the sunscreen |
Highest allowed amount | Up to 10% (Europe, India, Australia; EU Regulation 1223/2009, Annex VI entry 25); up to 6% (United States) |
Stays stable in sunlight? | Yes, and it is one of the strongest stabilisers of other filters |
How much soaks into skin? | Very little. It stays mostly in the top layer |
US (FDA) status | Approved. Final order OTC000039, effective 9 August 2026, up to 6% |
How Dermatocare Rates Tinosorb S
Here is how Tinosorb S scores against Dermatocare's own rating system.
Rating | Tinosorb S |
Skin type | All (oily, combination/normal, dry) |
Skin concern | Sun protection, tanning and photoageing, but not pigmentation or dark spots |
Acne-prone friendly | Yes |
Sensitive-skin friendly | Yes |
Beginner friendly | Yes |
Coverage | UVB and UVA II. Not UVA I on its own (it enables avobenzone's UVA I instead), no blue light, no visible light, no infra-red, no pollution |
Life stage match
· Adult: High
· Teens: High
· Pregnancy / Lactation: Medium (see the pregnancy question in the FAQs)
Children under 12. We follow Indian dermatologist guidance, which prefers mineral sunscreen for children (Kohli et al., 2025). That means zinc oxide or titanium dioxide, not chemical filters, and Tinosorb S is a chemical filter. Dermatocare applies that up to the age of 12. The US FDA cleared bemotrizinol for children six months and older in 2026, so you will see that figure quoted. Our position is more cautious than the American one, and deliberately so. From 13 onwards Tinosorb S is a high match, which is why the Teens line above reads High.
Why not pigmentation? Pigmentation, especially melasma, is driven largely by visible light, and Tinosorb S does nothing at all in the visible range. Clearing or preventing pigment needs a tinted, iron-oxide sunscreen.
What Is Tinosorb S?
Tinosorb S is a new-generation chemical filter. It is an oil-soluble molecule that dissolves completely into the oily part of a sunscreen, and it works purely by absorbing UV. Unlike Tinosorb M, it does not scatter light.
Tinosorb S is a unique chemical filter that has two absorption peaks, one at about 310 nm in the UVB range and one at about 343 nm in the UVA II range, so a single ingredient covers ground that usually takes two filters (BASF technical data). Its manufacturer describes it as the most efficient oil-soluble broad-spectrum filter available, and as an outstanding stabiliser for filters that are not stable on their own.
What Are Tinosorb S's Main Jobs in a Sunscreen?
Inside a sunscreen, Tinosorb S is asked to do more than one thing. Here is how formulators actually put it to work.
Job | What it means for you |
Broad-spectrum filter | Covers UVB and UVA II from a single ingredient, with peaks at about 310 nm and 343 nm. Its absorbance falls away after that, so deep UVA is not its own band. |
Photostabiliser | Stops fragile filters, especially avobenzone, from breaking down in sunlight. This is its standout strength, and it is directly proven for this filter, not borrowed from a relative. |
SPF booster | BASF reports that small amounts lift the overall SPF and UVA protection factor of the whole formula, so chemists can reach a high SPF without a heavy total filter load. This is manufacturer data rather than independent research. |
How Tinosorb S Works: Its Mechanisms of Action
Tinosorb S blocks UVB and UVA II, fading after that, so it needs avobenzone for the deep UVA. It protects the skin through two actions:
1. It absorbs UV. Its molecules soak up UV rays and release the energy as a tiny, harmless amount of heat. It has two absorption peaks, at roughly 310 nm and 343 nm, so one molecule handles both the burning rays (UVB) and the mid-range ageing rays (UVA II).
2. It steadies the other filters. This is the part that sets it apart. Some filters, avobenzone above all, fall apart in sunlight and stop working partway through the day. Tinosorb S prevents that breakdown, and it does so in a dose-dependent way: the more you add, the better protected avobenzone is (Chatelain and Gabard, 2001).
What Does Tinosorb S Help Prevent?
Tinosorb S is a UV filter, not a treatment. It prevents sunburn and holds the rest of the formula steady, but the anti-ageing benefit comes through the combination of avobenzone and Tinosorb S.
It does not brighten, hydrate or rebuild collagen by itself. What it does is stop the UV damage that causes many common skin problems in the first place.
Concern (prevented, not treated) | How the sun causes it | What Tinosorb S does | Research anchor |
|---|---|---|---|
Skin ageing (lines, sagging, collagen loss) | Deep UVA rays reach the lower skin and break down collagen over years | Does not cover deep UVA itself, but keeps avobenzone stable so that avobenzone's deep UVA protection lasts the day instead of fading by lunchtime | |
Tanning and UV-driven dark spots | UVA and UVB together push the skin to make more melanin | Covers the full UV range, lowering the UV trigger for extra pigment. This covers UV-driven pigment only. Visible-light-driven melasma needs a tinted, iron-oxide sunscreen | |
Losing protection during the day | Avobenzone can lose much of its strength within an hour or two of strong sun | Prevents that breakdown in a dose-dependent way, holding SPF and UVA ratio steady even after heavy sun exposure | |
Sunburn and its long-term consequences | UVB damages skin cell DNA directly | Absorbs strongly at 310 nm, the heart of the UVB range | BASF technical data; FDA order OTC000039, 2026 |
What Does the Research Actually Show?
Tinosorb S is better evidenced than most filters, including a human blood study, which is exactly why the FDA approved it in 2026.
Below are the actual studies behind the claims on this page, with what each one found.
Study | What it looked at | What it found |
|---|---|---|
Chatelain and Gabard, Photochem Photobiol, 2001 | Whether Tinosorb S could stop avobenzone and octinoxate breaking down in sunlight | It prevented avobenzone's breakdown in a dose-dependent way, holding SPF and UVA ratio steady even after 30 minimal erythemal doses of light. It protected octinoxate too. This study tested Tinosorb S itself. |
D'Ruiz et al., Regul Toxicol Pharmacol, 2023 | How much bemotrizinol enters the bloodstream when used heavily, in real people | Under maximum-use conditions with a 6% product, blood levels rarely crossed the FDA's 0.5 ng/mL threshold. Only 113 of 3722 blood samples went above it, never twice in a row, with no build-up over time. Note: this study was funded and staffed by DSM, which sells the ingredient. |
Ashby et al., Regul Toxicol Pharmacol, 2001 | Whether Tinosorb S has hormone-like activity | No binding to estrogen or androgen receptors, and no activity in the immature rat uterotrophic test. The authors put this down to the molecule being too large to fit hormone receptors. |
FDA scientific review, order OTC000039, 2026 | The full safety package behind the US approval | Not a skin or whole-body carcinogen in rats, with a no-effect level of 1000 mg/kg per day. Tested across the whole reproductive cycle in rats and for effects on unborn rabbits, with no ingredient-related harm at any dose. Calculated margin of safety of 851 for a 6% sunscreen. |
Badaoui, Contact Dermatitis, 2024 | A case of allergic contact dermatitis traced to Tinosorb S in a sunscreen | Confirmed a genuine, patch-test-proven allergy to this filter in one patient. Rare, but real, and worth knowing if sunscreens have ever given you a rash. |
Nitulescu et al., Cosmetics, 2023 | A broad review of UV filters, their coverage and stability | Places bemotrizinol among the broad-spectrum, photostable filters used to build modern high-SPF products. |
Is Tinosorb S Good for Indian Skin and Climate?
Yes, Tinosorb S suits Indian conditions because it does not have a white cast and it holds up in heat, but pair it with avobenzone or the deep UVA is missing.
No white cast at all. Because Tinosorb S dissolves completely into the formula, there are no particles to sit on the skin and go grey. Mineral filters can leave an ashy film on medium and deep skin, and even low-cast particle filters can show up at high amounts. A dissolved filter simply cannot do this. For brown and deeper skin, that is a real practical advantage.
Reliable UVA protection, but in combination with avobenzone. Deep UVA is the main driver of tanning and dark spots in brown skin, and Tinosorb S does not cover deep UVA by itself. What it does is keep avobenzone stable, and avobenzone is the filter that covers it. So on an Indian label, look for Tinosorb S next to avobenzone. That pairing is where the real all-day UVA protection comes from, and neither half delivers it alone.
It holds up in heat and strong sun. It is highly photostable, so it does not break down the way older filters can over a long, bright, sweaty Indian day. Reapplying still matters, because heat and sweat physically wipe sunscreen off, and no filter can prevent that.
Very low skin absorption. It is a large molecule that stays mostly in the top layer of skin. A maximum-use study in people found that even with heavy application of a 6% product, blood levels rarely rose above the FDA's threshold of concern (D'Ruiz et al., 2023).
One important caution. Tinosorb S gives no protection against visible light, and visible light is a major trigger of pigmentation, especially melasma, in brown and deeper skin. If your main concern is melasma or stubborn dark patches, a sunscreen built on Tinosorb S alone will not do the job, no matter how high the SPF. You need a tinted, iron-oxide sunscreen on top of it or instead of it. Treating a high-SPF Tinosorb S sunscreen as complete pigmentation cover gives a false sense of security.
Who Should Use Tinosorb S?
It is an everyday choice for any skin type, provided the formula has a deep UVA partner because it protects broadly, stays mostly on the surface and leaves no cast.
If this is you | Why Tinosorb S fits |
|---|---|
You want simple daily broad-spectrum protection | It covers UVB and UVA II from one ingredient and stabilises the deep-UVA filter beside it, so a Tinosorb S plus avobenzone sunscreen is a dependable everyday choice. |
You have brown or deep skin | It dissolves fully, so there is no white cast at all, not even a faint one. |
You hate the feel of mineral sunscreens | It sits in the oil phase and disappears into the formula, so textures can be much lighter and more elegant than mineral equivalents. |
You are acne-prone | The filter itself does not clog pores. The texture of the finished product is what matters, so choose a light gel or fluid. |
You use retinoids or exfoliating acids | It gives steady, all-day UVA protection for skin that is more sun-sensitive than usual. |
You want your sunscreen to still work at 4pm | Photostabilising fragile filters is its single strongest, best-evidenced property. |
Two exceptions to keep in mind. If your main concern is pigmentation driven by visible light, such as melasma, Tinosorb S on its own is not enough, so pair it with a tinted, iron-oxide sunscreen. And if sunscreens have given you a rash before, see the sensitive-skin question in the FAQs.
How to Use a Tinosorb S Sunscreen
You only ever meet Tinosorb S inside a finished sunscreen, so using it well really means using the sunscreen well.
Apply it last. Put it on as the final step of your morning skincare, after moisturiser and before makeup, and give it 2 to 3 minutes to settle into an even layer.
Use enough. About two finger-lengths for the face and neck. Using too little is the single most common reason people do not get the SPF on the label.
Reapply every 2 hours outdoors. Photostable means the filters do not break down from UV. It does not stop the sunscreen being sweated, rubbed or washed off, so you still need to top it up.
Layer it over an antioxidant. A vitamin C serum underneath mops up the stray damage that slips through, while the sunscreen blocks the UV.
Add a tint if pigmentation is your concern. A tinted, iron-oxide layer is the only way to cover the visible light that Tinosorb S misses entirely.
Bottom-line: Apply it last, use two finger-lengths, reapply every two hours outdoors.
What Does Tinosorb S Pair Well With?
Tinosorb S is a team player, and a few pairings are especially worth knowing.
Pairs with | What the combination gives you |
|---|---|
Avobenzone | The pairing that matters most. At Dermatocare, avobenzone only earns a deep UVA (UVA I) claim when it is paired with a stabiliser, and Tinosorb S is one of the four we accept, alongside octocrylene, Polyester-8 and ethylhexyl methoxycrylene. Without a partner, avobenzone retains only about a quarter of its strength after strong sun. So this combination is not a bonus, it is what makes the deep UVA protection real (Chatelain and Gabard, 2001). |
Octinoxate (ethylhexyl methoxycinnamate) | The same 2001 study showed Tinosorb S also protects octinoxate, which avobenzone otherwise destabilises. |
Tinosorb M (bisoctrizole) | BASF reports strong SPF synergy between the two, and Tinosorb M does earn deep UVA in its own right, which Tinosorb S does not. You get the dissolved absorber and the scattering particle in one formula, which is why they often appear together on Indian and European labels. |
Ethylhexyl triazone and iscotrizinol | Also flagged by BASF as synergistic, letting chemists reach a high SPF with less total filter load. |
Iron oxides (a tinted sunscreen) | This is the pairing that fixes Tinosorb S's one real gap, adding the visible-light cover it cannot provide. |
Antioxidants (like vitamin C) and ceramides | The antioxidant mops up stray free radicals, the ceramides support the skin barrier, and together they add repair on top of the sun protection. |
What Tinosorb S Cannot Do
It is not a skincare active. Any glow, hydration or brightening comes from the other ingredients in the sunscreen, not from the filter itself.
It does not remove the need to reapply. Staying stable in sunlight is not the same as staying on your face. Sweat, water and touch still wear it away.
It does nothing for visible or blue light. Not partly, not a little. It is a dissolved absorber with no scattering, and its coverage stops at 400 nm. For melasma and visible-light-driven pigment you need iron oxides.
It does not cover deep UVA on its own. Its absorbance falls away past about 343 nm, so we do not credit it with UVA I by itself. Avobenzone, Uvinul A Plus or Mexoryl carries that band, and the very far end past 380 nm is Mexoryl 400 only. Tinosorb S earns its place by keeping avobenzone alive, not by replacing it.
It does not cover infra-red or pollution. No UV filter does, whatever the packaging says.
It is capped lower in the United States. American products can use up to 6%, against 10% in Europe, India and Australia.
Bottom-line: It does not cover deep UVA, blue light or visible light, so it cannot prevent melasma on its own.
How to Choose the Right Tinosorb S Sunscreen
Tinosorb S shows up in a great many sunscreens, so here is how to pick one that earns its place in your routine.
Check it is genuinely broad-spectrum. Look for a high SPF alongside a strong UVA marking, such as PA++++ or the UVA-in-a-circle symbol. Tinosorb S helps, but the whole formula has to deliver.
See what it is paired with. It works hardest next to avobenzone, because that is where its photostabilising strength pays off. Alongside Tinosorb M you get absorption plus scattering.
Match the texture to your skin. Because Tinosorb S sits in the oil phase, formulas range from very light fluids to rich creams. Oily and acne-prone skin usually prefers a light gel or fluid, dry skin does better with a cream carrying ceramides.
For pigmentation or melasma, pick a tinted version. The iron oxides in a tinted sunscreen add the visible-light cover that Tinosorb S cannot give at all.
Do not pay extra for the "new FDA-approved filter" label. In India this ingredient has been available for years at up to 10%. The 2026 approval is news in America, not here.
Bottom-line: Check for a deep UVA partner first and a high PA rating second.
What Does the 2026 FDA Approval Actually Change?
For Indian readers, less than the headlines suggest, but it is worth understanding.
What happened. On 10 June 2026 the FDA issued final administrative order OTC000039, adding bemotrizinol to the list of permitted actives in the over-the-counter sunscreen monograph. It took effect on 9 August 2026. The agency found it generally recognised as safe and effective at up to 6% in broad-spectrum sunscreens, for adults and children six months and older. It is the first new sunscreen active added in the United States since 1999.
Why it took so long. The United States regulates sunscreen as an over-the-counter drug, not a cosmetic, so a new filter needs a full drug-style safety package. That is why American sunscreens have run on about ten filters while Europe has had more than thirty. Bemotrizinol went through the FDA's newer testing route, which is why studies like the D'Ruiz maximum-use trial exist at all.
The two catches. The American cap is 6%, not 10%, so imported US sunscreens will carry less of it than Indian ones. And DSM holds 18 months of exclusivity from 9 August 2026, so American products containing it will appear gradually rather than all at once.
Frequently asked questions
Yes, and it is one of the most photostable filters in use. It does not break down meaningfully during sun exposure, which is unusual, and it is stable enough to protect its neighbours as well. That second ability, stabilising other filters, is what formulators value most about it.
References
Chatelain E, Gabard B. Photostabilization of butyl methoxydibenzoylmethane (Avobenzone) and ethylhexyl methoxycinnamate by bis-ethylhexyloxyphenol methoxyphenyl triazine (Tinosorb S), a new UV broadband filter. Photochem Photobiol. 2001;74(3):401-406. doi:10.1562/0031-8655(2001)074<0401:pobmaa>2.0.co;2. PMID: 11594052. View on PubMed (Lead author employed by Spirig Pharma Ltd, a sunscreen manufacturer.)
D'Ruiz CD, Plautz JR, Schuetz R, Sanabria C, Hammonds J, Erato C, Klock J, Vollhardt J, Mesaros S. Preliminary clinical pharmacokinetic evaluation of bemotrizinol, a new sunscreen active ingredient being considered for inclusion under FDA's over-the-counter (OTC) sunscreen monograph. Regul Toxicol Pharmacol. 2023;139:105344. doi:10.1016/j.yrtph.2023.105344. PMID: 36738872. View on PubMed (Study sponsored by DSM Nutritional Products, which manufactures and sells this filter.)
Ashby J, Tinwell H, Plautz J, Twomey K, Lefevre PA. Lack of binding to isolated estrogen or androgen receptors, and inactivity in the immature rat uterotrophic assay, of the ultraviolet sunscreen filters Tinosorb M-active and Tinosorb S. Regul Toxicol Pharmacol. 2001;34(3):287-291. doi:10.1006/rtph.2001.1511. PMID: 11754532. View on PubMed
Badaoui A. Allergic contact dermatitis to bis-ethylhexyloxyphenol methoxyphenyl triazine (Tinosorb S) in a sunscreen: An emerging allergen? Contact Dermatitis. 2024;91(5):443-445. doi:10.1111/cod.14647. PMID: 39011994. View on PubMed
Nitulescu G, Lupuliasa D, Adam-Dima I, Nitulescu GM. Ultraviolet Filters for Cosmetic Applications. Cosmetics. 2023;10(4):101. doi:10.3390/cosmetics10040101. View the paper
Kohli M, Srinivas CR, Saraswat A, et al. Practical Recommendations for Indians on Sunscreen Use, A Modified Delphi Consensus by Indian Sunscreen Forum (PRISM-ISF). Journal of Cosmetic Dermatology. 2025;24(9):e70441. doi:10.1111/jocd.70441. PMID: 40955142. PMCID: PMC12439021. Read the full consensus (Recommends inorganic filters, zinc oxide and titanium dioxide, in preference to any other sunscreen for children, and no sunscreen under six months. It sets no upper age limit, so Dermatocare's cut-off of 12 years is our own application of it.)
U.S. Food and Drug Administration. Amending Over-the-Counter Monograph M020: Sunscreen Drug Products for Over-the-Counter Human Use. Final Administrative Order OTC000039, issued 10 June 2026, effective 9 August 2026. (Bemotrizinol generally recognised as safe and effective at up to 6% in broad-spectrum sunscreens for adults and children six months of age and older.)
U.S. Food and Drug Administration, Center for Drug Evaluation and Research. Scientific review supporting order OTC000039 (bemotrizinol), December 2025. (Reports no dermal or systemic carcinogenicity in rats at a no-observed-adverse-effect level of 1000 mg/kg body weight per day, no ingredient-related effects in rat reproductive and rabbit developmental toxicity studies, and a calculated margin of safety of 851 for 6% use in sunscreen.)
Regulation (EC) No 1223/2009 on cosmetic products, Annex VI, entry 25 (Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine, maximum 10% in the ready-for-use preparation).
BASF Personal Care. Tinosorb S Technical Information, PRD 30481068, revision 1.0. (Documents the INCI name, CAS number 187393-00-6, molecular weight 628 g/mol, oil solubility, absorption at 341 nm, photostability, and synergy with bisoctrizole, ethylhexyl triazone and iscotrizinol.)
Bureau of Indian Standards. IS 4707 (Part 4):2022, list of ultraviolet filters permitted in cosmetics. (Aligned with the European Union list, permitting bemotrizinol up to 10%.)
This guide is for education and is based on published research and safety reviews available at the time of writing. It is not a substitute for personal medical advice. Whether an ingredient suits you depends on the full product and on your own skin.