Mexoryl SX (Ecamsule): Powerful Photostable UVA Protection
Mexoryl SX (Terephthalylidene Dicamphor Sulfonic Acid / Ecamsule) is one of the most photostable UVA filters available. It provides strong, long-lasting protection in the critical UVA-II range and serves as the UVA anchor in Aqualogica sunscreens, helping achieve verified PA++++ ratings and broad-spectrum performance.
Water-soluble and highly stable, it distributes evenly in gel formulations for consistent, comfortable protection that withstands sweat and humidity.
Mexoryl SX at a Glance
The essentials before we dive into the science.
| Attribute | Detail |
|---|---|
| INCI Name | Terephthalylidene Dicamphor Sulfonic Acid |
| Alternate Names | Ecamsule, TDS |
| Ingredient Type | UV Filter — UVA |
| Category | UV Filter, UVA |
| Best For | Strong, photostable UVA protection, extending broad-spectrum coverage into the critical UVA-II range, long-wear SPF performance in gel and water-based formulas |
| Concentration | Up to 10% (EU and India approved limit) |
| Properties | Non-comedogenic (Rating 0), Zero irritation potential, Non-photosensitizing, Highly photostable, Water-soluble |
| Ingredient Strength | Gentle: Functions passively as a UV filter. No adjustment period needed. |
| Suitable for Sensitive Skin | Yes: Low sensitization potential. Well-tolerated across sensitive and reactive skin types in gel formulations. |
What Is Mexoryl SX and Why Do People Use It?
Mexoryl SX is a highly photostable UVA filter that remains effective even after prolonged UV exposure. Aqualogica uses it in sunscreens like Glow+ Dewy Gel to deliver reliable, long-wear protection against deep tanning and photoaging in India’s intense UVA environment.
People reach for Mexoryl SX to:
• Prevent deep tanning and photoaging from UVA rays that penetrate glass and persist all day.
• Achieve true broad-spectrum coverage with high PA++++ ratings.
• Enjoy comfortable, non-greasy protection in lightweight gel textures.
How Mexoryl SX Works: The Science
Mexoryl SX absorbs UV radiation across the UVA spectrum (peak at ~345nm in UVA-II). It converts the absorbed energy into harmless heat, preventing it from damaging deeper skin layers. Its exceptional photostability ensures consistent protection without degradation.
What Mexoryl SX Does: Functional Role
| Functional Role | Category | Sub-role Mechanism |
|---|---|---|
| UVA Protection | UV Filter | Absorbs UVA rays and converts energy to heat. |
| Photostable Anchor | Broad-Spectrum Support | Stabilizes other filters and maintains efficacy over time. |
Benefit intensity: Preventive: Full UV protection from first application. Must be reapplied every 2 hours under sun exposure.
Concerns Mexoryl SX Targets (with Root Cause & Severity)
| Skin Concern + Root Cause | Concern Severity |
|---|---|
| Deep Tanning & Photoaging: Triggered by long-wave UVA rays that penetrate glass and persist throughout the day during indoor office hours and commuting. | Suitable for all sun protection needs, from daily incidental indoor exposure to extended outdoor use. |
| Stubborn Pigmentation: Triggered by cumulative daily UVA exposure stimulating melanocytes in melanin-rich Indian skin. | All skin types, with low irritation potential. |
Why Mexoryl SX Suits Indian Skin & Climate
India’s high UV Index and UVA intensity persist from sunrise to sunset. UVA penetrates windows and car glass, causing deep tanning and pigmentation in Fitzpatrick IV-VI skin. Mexoryl SX’s photostability ensures reliable protection during long commutes, office hours near windows, and sweaty outdoor exposure without breaking down.
The Evidence: What Research Shows
| Study | Finding | Reference |
|---|---|---|
| Photochem Photobiol Sci (2010) | Mexoryl SX is among the most photostable UVA filters; minimal degradation under UV exposure. | Shaath NA review |
| Aqualogica CTRI Registration | Glow+ Dewy Gel Sunscreen — in-vivo tested SPF 50+, PA++++, critical wavelength 381nm. | CTRI/2025/03/083452 |
Result timeline: Immediate UVA protection from the moment of application. Maintains photostability without degrading under continuous UV exposure.
Who Should Use Mexoryl SX?
| Skin Type & Severity | How to Choose the Right Product |
|---|---|
| All skin types, including sensitive and oily. | Gel-based sunscreens for lightweight, non-greasy daily protection. |
How to Use Mexoryl SX: Step by Step
How to Start
Daily morning protection
Patch Test
Routine safety check
Tips to Get Started
For maximum efficacy
Sun Safety & Consistency
Morning use only. Reapply every 2 hours outdoors. Provides immediate protection upon application.
What Mexoryl SX Cannot Do
It is not a standalone sunscreen. It works as part of a complete broad-spectrum formula.
It does not replace reapplication. Must be reapplied every 2 hours during sun exposure.
What Mexoryl SX Combines With
| Ingredient | Compatibility | Benefit of Pairing |
|---|---|---|
| Avobenzone | Excellent | Complementary UVA coverage across different ranges. |
| Tinosorb M | Excellent | Photostabilization for overall formula stability. |
Build Your Sunscreen Routine with Aqualogica
Choose gel-based sunscreens featuring Mexoryl SX for reliable UVA protection.
Glow+ Dewy Gel Sunscreen SPF 50+ PA++++ 50g
Lightweight daily protection: Gel texture with strong UVA defense and comfortable wear.
Shop NowIlluminate+ Dewy Sunscreen SPF 50+ PA++++ 30g
Bright + protected: Combines UVA protection with skin-brightening benefits.
Shop NowFrequently Asked Questions About Mexoryl SX
A: It provides stable UVA protection against deep tanning and pigmentation that Indian skin is highly prone to, even indoors near windows.
A: Every 2 hours during outdoor exposure or after sweating.
A: Yes, it has low irritation potential and performs well in gentle gel formulations.
What Research Says About Mexoryl SX
- Photochem Photobiol Sci (2010): Highly photostable UVA filter with minimal degradation.
- Aqualogica CTRI Registration (2025): In-vivo tested SPF 50+, PA++++ performance.
