Protection against the harmful effects of sunlight upon the skin is the main benefit of using sunscreen with Mexoryl SX. As of 2015, it is only available in products by L'Oreal, which developed and patented the chemical in the early 1980s.
Mexoryl is the trade name for ecamsule or terephthalylidine dicamphor sulfonic acid, according to the International Nomenclature of Cosmetic Ingredients. Ecamsule is an organic compound that possesses a natural chemical stability throughout exposure to ultraviolet radiation from the sun.
Ultraviolet radiation occurs in many different wavelengths or ranges known as nanometers. All of the ultraviolet wavelengths are potentially harmful to the skin, but some are more harmful than others, such as UVA and UVB. UVA and UVB have a collective nonamoeter range of 230 to 700, which are the same ultraviolet light ranges that Mexoryl effectively filters and blocks.
Mexoryl blends with other key sunscreen chemicals that tend to degrade more quickly when exposed to UVA and UVB, such as avobenzene, octocrylene, zinc oxide and titanium dioxide. The result is broad-spectrum ultraviolet protection for a slightly longer period than products that do not contain Mexoryl.
Mexoryl has a low rate of percutaneous absorption, which means it does not readily enter the body through unbroken skin. Mexoryl is present in L'Oreal's Ombrelle sunscreen product and in the Anthelios line of products by La Roche-Posay, which L'Oreal owns.