Charlize Theron has said she believes women "come into their prime" in their 40s.

The 39-year-old actress told Women's Wear Daily it's strange that the beauty world is focused on people in their 20s, who she said have yet to learn the real meaning of confidence and attractiveness.

She said: "I think that women find their strength and power in their sexuality, in their sensuality within, [through] getting older and being secure within that."

Charlize - who is dating Hollywood star Sean Penn - went on: "It's ironic that we've built the beauty world around 20-year-olds, when they have no f****n' concept about wisdom, what life is about, having a few relationships below [their] belt and feeling hardships, to grow into [their] skin and feel confident within [themselves] and to feel the value of who [they] are, not because of a man or because of something like that. And I think that's such a beautiful thing.

"And that's why I think people say women come into their prime in their 40s. And then for some reason our society just wants to go... it's like a dead flower. [Takes a flower from a vase]. It's like we wilt for some reason."

The Oscar-winner said in comparison men are "like fine wines", in that they are considered to get better with age.

"It's such a misconception, and it's such a lost opportunity because that's when I think women are really in the true moment of their sensuality," she said.