Within minutes, some of the biggest names in the business sent messages of support.
Oprah kickstarted the well wishes and simply wrote, "Feel better!"
While Gwyneth Paltrow was a tad jealous, commenting: "I kind of want to crawl in to that dog pile."
"Oh no, feel better, friend," Natalie Portman added.
But it was January Jones who said what we're all thinking, as she wrote: "Well, at least you look 12."
But there's no need to fear, as Witherspoon is back up and out.
In a second post, the mother-of-three revealed that she is at work once again.
"Sometimes you just have to put on some lipgloss and pretend to be psyched!" she captioned a photograph of herself looking spritely.
Proof that a day spent lounging on the sofa with puppy cuddles should be scheduled into everybody's diary.