L"Oréal S.A. is a French cosmetics company headquartered in Clichy, Hauts-de-Seine with a registered office in Paris. It is the world"s largest cosmetics company and has developed activities in the field of cosmetics, concentrating on hair colour, skin care, sun protection, make-up, perfumes and hair care, the company is active in the dermatology, toxicology, tissue engineering, and biopharmaceutical research fields and is the top nanotechnology patent-holder in the United States. The company is a component of the Euro Stoxx 50 stock market index.