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Ingredient · INCI reference

Terephthalylidene Dicamphor Sulfonic Acid

a.k.a. Ecamsule (Mexoryl SX)

CAS 92761-26-7

Terephthalylidene Dicamphor Sulfonic Acid, known as Ecamsule or Mexoryl SX, is a newer-generation organic UVA filter covering UVA1 and UVA2. It is approved up to 10% in the EU, Japan (quasi-drug), and Korea, and in the US only via NDA up to 3%. It is photostable, EWG rates it 1.

Modern organic Next-gen photostable chemical filters. Gen · new organic
01 Spectrum coverage UVA1 · UVA2
UVB 290–320nm UVB (290–320nm) — not covered UVA-II 320–340nm UVA-II (320–340nm) — covered UVA-I 340–400nm UVA-I (340–400nm) — covered
02 Regional approval · max %
JP ✓ 10% Japan: Approved · max 10% KR ✓ 10% South Korea: Approved · max 10% EU ✓ 10% Europe: Approved · max 10% US — 3% United States: No data · max 3%
03 Safety profile
EWG score
1
Reef-toxic
No
Endocrine disruptor
No
Comedogenicity
0
Reference

Frequently asked questions

What is Mexoryl SX?

Mexoryl SX is L'Oreal's trade name for Terephthalylidene Dicamphor Sulfonic Acid, also called Ecamsule. It is a photostable organic filter focused on UVA1 and UVA2 coverage.

Why is Ecamsule rare in US sunscreens?

In the US it is approved only under a New Drug Application route, capped at 3%, and tied to specific approved formulations rather than the general OTC monograph. That limits how broadly it appears.

What part of the UV spectrum does Ecamsule cover?

It covers UVA1 and UVA2. It contributes to long-UVA protection associated with skin aging and pigmentation, but it does not cover UVB and is paired with UVB filters in finished formulas.

Is Ecamsule photostable?

Yes. It is a photostable UVA filter, which is part of why it has been valued in formulations seeking durable UVA protection over the wear window.

Products in catalogue

Containing Terephthalylidene Dicamphor Sulfonic Acid