Lenoir, 30, is believed to have taken "large quantities" of drugs and alcohol after boyfriend Claude Makélélé, the Paris St Germain footballer, discovered her slumped on the floor.
French news agency AFP confirmed: "Her life is not in danger after this act which our sources have confirmed was an attempted suicide."
Makélélé - who played for Chelsea from 2003 to 2008 - met Lenoir in 2004 and the couple have a 5-year-old son together.
Lenoir has starred in five French films, including Asterix and Obelix. She also appeared in Rush Hour 3.