In 1985, he returned to France as General Manager of L'Oreal Paris, where he oversaw a number of key launches and successes, including Studio Line, Plénitude and Elsève.

In 1994, he became managing director of L'Oréal Germany, where he played a key role in dealing with issues related to European markets, at the time suffering a slowdown in growth.

[4] Known for his views on the "universalization" of beauty,[6] Agon began the process of opening three new L’Oréal factories outside France – in Mexico, Egypt and Indonesia.

[7] Agon is also dedicated to environmental protection and aims to reduce the company's carbon dioxide emissions, water consumption, and waste production by 50% between 2005 and 2015.

[4] Agon, along with 16 other executives and investors such as Stéphane Richard and Liliane Bettencourt, signed a petition in 2011 calling for a tax on the rich, as a way of contributing to society during troubled times.