Ingredient · Organic UVA Filter
Mexoryl SX (UVA Filter)
INCI · Terephthalylidene Dicamphor Sulfonic Acid
Related names and forms: Ecamsule. This list does not indicate synonyms or exact ingredient matches.
Mexoryl SX is a water-soluble, photostable UVA filter developed by L'Oreal. An important distinction: 'Mexoryl SX' is a trade name; its label INCI equivalent is 'Terephthalylidene Dicamphor Sulfonic Acid' (generic name: ecamsule). It protects particularly in short UVA. Water solubility distinguishes it from oil-soluble filters: it works in the water phase, allowing a two-phase water-and-oil protection system alongside oil-phase filters. It often pairs with oil-soluble Mexoryl XL to create a complementary UVA-UVB system. Regional regulatory differences are notable; some markets have had different approval pathways, and Klaris does not state specific regulatory values without sources. Proper assessment considers its UVA contribution, water/oil phase balance and accompanying filter combination together.
i. Cosmetic Functions
Frequently Discussed Effects
The following headings summarise areas of effect frequently discussed in the literature; visible results in each area require regular use and a suitable formula.
UVA Protection
A photostable organic filter particularly effective in short UVA.
Water-Phase Solubility
Its water-soluble structure offers complementary protection alongside oil-phase filters.
Combination Context
Often assessed with Mexoryl XL and UVB filters in a broad-spectrum combination.
Mechanism
What Happens Within the Skin?
The following points summarise mechanisms from dermocosmetic literature in plain English. Klaris presents them as background information to help readers understand the context, not as medical claims.
Step 1
UVA (Short-UVA) Absorption
A photostable organic filter particularly effective in short UVA; broad-spectrum coverage needs complementary UVB and long-UVA filters.
Step 2
Water-Phase Solubility
Its water-soluble structure distinguishes it from oil-soluble filters; it works in the formula's water phase.
Step 3
High Photostability
Its light-resistant structure supports UVA protection throughout the day.
Step 4
Complementing Mexoryl XL
Creates a balanced water-and-oil-phase protection system alongside oil-soluble Mexoryl XL.
ii. Role in the Formula
How Is It Read on a Label?
Mexoryl SX is a water-soluble UVA filter regulated by cosmetic legislation. Alongside oil-soluble filters, it helps establish balanced protection across water and oil phases. Conditions of use are assessed within formula and market regulations.
A Closer Look · pH, Stability, Synergy
Mexoryl SX has a relatively unusual cosmetic feature: it is a water-soluble UVA filter. While most organic filters dissolve in the oil phase, it works in water, allowing two-phase water-and-oil protection alongside oil-soluble filters and adding formulation flexibility. It often pairs with oil-soluble Mexoryl XL in a complementary UVA-UVB system. Photostability supports UVA protection throughout the day. 'Mexoryl' is a L'Oreal trade family, but that does not make the ingredient a mysterious or brand-specific substance: it is read on labels by its generic INCI name, Terephthalylidene Dicamphor Sulfonic Acid. The patent context is a supply matter limiting availability to certain brands. The idea that water-soluble filters 'wash away' is misleading; film-forming ingredients can give the filter water resistance within a formula. Regional approval differences are notable. Klaris describes conditions in general terms without unsourced specific regulatory values. Newer-generation filters are discussed in a low-irritation context for sensitive profiles. Klaris considers UVA contribution, water/oil phase balance, the filter combination and texture as a whole.
Typical Concentration Range
1% - 10% (within conditions set by regulations)
Ingredient Family
UV Filters
iii. Sensitivity Advisory
A Note on Extra Care in Context
Generally described as low-irritation, although individual sensitivity may be reported in sensitive profiles. Patch testing is a measured approach.
A sensitivity advisory is not an instruction for use; where individual health circumstances, pregnancy or known sensitivities are involved, discussing the decision with your doctor may be a more contextual approach.
Common Misconceptions
Frequently Confused Points
Common Belief
Mexoryl is a brand, not an INCI name; I cannot find it on the label.
A More Contextual Reading
'Mexoryl SX' is a trade name. Its INCI equivalent appears as 'Terephthalylidene Dicamphor Sulfonic Acid' (generic: ecamsule), so it can be identified in the INCI list.
Common Belief
Mexoryl SX provides a broad spectrum alone.
A More Contextual Reading
Mexoryl SX focuses on UVA, particularly short UVA. A broad spectrum requires complementary UVB and long-UVA filters.
Common Belief
A water-soluble filter washes away and is useless.
A More Contextual Reading
The filter works in the water phase. Film-forming ingredients can provide water resistance; solubility alone does not mean it lacks staying power.
Scientific Basis
Sources and Their Scope
The following headings indicate areas of research; they are not citations of a specific publication or confirmation that every statement on this page has been verified. The links provided should be read with their individual scope in mind.
- International INCI / CosIng database
- Regulatory authority documents (EU SCCS, TİTCK)
- Dermocosmetic research publications
TİTCK, SCCS and similar regulatory authorities are mentioned in the context of publicly available regulation; Klaris has no official endorsement, partnership or collaboration with these institutions.
Source Links
Database records provide ingredient identity and registration information; on their own, they do not establish the effect of a finished product or its suitability for a profile. Search links are not specific research papers.
iv. Related Ingredients
Ingredients Often Read Together
Ingredient · Broad-Spectrum Organic Filter
Mexoryl XL (Broad-Spectrum Filter)
INCI · Drometrizole Trisiloxane
Ingredient · Organic UVA Filter
Uvinul A Plus (UVA Filter)
INCI · Diethylamino Hydroxybenzoyl Hexyl Benzoate
Ingredient · Chemical (Organic) UV Filter
Avobenzone (Chemical UV Filter)
INCI · Butyl Methoxydibenzoylmethane
v. UV Filters Family
Other Ingredients in the Same Family
Explore ingredients in the same functional family to deepen your reading of formulas.
vi. Academy · Related Reading
For a Closer Look
Klaris · Example Analyses
How Does Mexoryl SX (UVA Filter) Feature
in Your Products?
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