"I had my mouth done when I was 27. It was a botched job," she confessed to French publication Le Monde.
"Obviously, if I had liked my mouth I wouldn’t have had it redone.
"If a man or woman has something redone it is because he or she can no longer live with that part of their body, it is no longer bearable.
"Either they get help and find the strength to fight [the need to have plastic surgery] or they proceed with the act."
Emmanuelle, best known for starring alongside Tom Cruise in the first Mission: Impossible film, says she was "profoundly affected" by her plastic surgery experience and wouldn't do it again.
"[Plastic surgery] is a grave act in which you don’t necessarily foresee all the consequences," she said.
"Just the idea of an injection these days devastates me. So I don’t know how I will get through these stages [of ageing]".
Despite her needle phobia, Emmanuelle is sympathetic to her acting peers who undergo cosmetic procedures in order to apear fresh on screen.
"It is not easy to grow old in this business, when you are a woman above all, in the cinema," she said.
Reckon you can tell a plumped-up lip from a natural pout? Check out our Trout pouts: real or fake? slideshow and see how good your surgery-spotting skills are.