The 44-year-old actress - who has three-year-old daughter Valentina with husband Francois-Henri Pinault - has just launched her own affordable skincare range, Nuance. She has also wrapped up filming on comedy Here Comes The Boom, and said that she can't help but feel tired 24/7.
Motherhood is 'all-consuming', she told USA Today.
'And it's not temporary. I went out with my husband and my agent last night. They were making fun of me because I'm all the time, 24/7, 'Oh, I'm so tired.'
'They were laughing. I was laughing, too, but inside I wanted to cry because I'm so tired. I'm so happy. Happiness is exhausting.'
Talking about her beauty range, she said that unlike some celebrities who simply put their name to a product, she has tried and tested every single item.
'I've been working on this for years. I burn my face, my eyes, trying this (expletive). I have very sensitive skin. The stuff is really, really, really good,' she said.