Reese Witherspoon was so bothered by a magazine article that called her washed up, she launched the hit HBO show “Big Little Lies” — and eventually got women at the network equal pay, according to a new Vanity Fair profile.

“An actress came up to me at a party and said, ‘Do you know what you’ve done?’ I had no idea what she was talking about,” Witherspoon tells the April 2020 issue.

“[HBO] had called her agent to rewrite her contract. She was then paid twice as much as she had been.”

Witherspoon, 43, says in the interview that a harsh, throw-away line in a 2012 New Yorker magazine profile irked her into taking action.

The star — who was then 36 and not getting much work — teamed up with her talent-agent husband, Jim Toth, to create her own production company.

The goal was to create better roles for actresses of all ages — and get more women in directors’ chairs, she says, recalling the bad old days on movie sets.

“I can remember being in pictures in which I was the only woman on the set and there would be 150 men,” Witherspoon says. “Maybe there would be a couple of women in wardrobe. I remember when I was a kid, I would find them and cling to them.”

But after executives at HBO fell in love with the Monterey, California-set drama “Big Little Lies,” Witherspoon had leverage with executives, she recalls.

During negotiations, she demanded that honchos pay women on set the same rate as men, according to the article.

She adds that it’s important for women in Hollywood to share their pay rates with each other to help keep studios honest.

And the best way to ensure never going out of style is to have a sharp sense of humor, she says.

“You can’t be rendered obsolete if you just keep being funny. Guess what gets rendered obsolete: Your boobs go south, your face goes south, your ass goes south, but you can always be funny,” Witherspoon tells the mag. ‘”Funny doesn’t sag.”