Jessica Chastain's skin looks "better" if she slaps her face.

The 47-year-old actress shared her make-up routine in a new video, and revealed the bizarre tip she picked up while working on a job, and even though she doesn't understand how it seems to work for her, she's happy with the results.

The Molly's Game star kicked off her routine in Vogue's Beauty Secrets series by applying True Botanicals Chebula Active Serum to her skin and letting it “absorb.”

“I worked with a make-up artist once who just kept hitting me. She kept doing this to my skin with the products. I realized it made my skin look better. Don’t know what that is," she said with a chuckle.

The Interstellar star stressed her belief that "taking care of your skin is an extension of taking care of yourself" as she applied eye masks and a tinted sunscreen.

Chastain used nude and brown colors from a Makeup by Mario palette, as well as white eyeliner in her waterline, on her eyes.

“I love pops of color in my wardrobe, but in terms of my face, earth tones all the way," she stated.

READ MORE: Charli XCX Embodies ‘Brat’ Energy as the New Face of SKIMS in Sultry Campaign

The award-winning star admitted that she "doesn't drink enough" water to have a dewy complexion so hydrates her skin with True Botanicals Renew Pure Radiance Oil, before applying Mario Badescu Drying Lotion and Supergoop’s Unseen Sunscreen to get a glow before applying foundation.

“I like this Charlotte Tilbury [Flawless Filter Foundation]. The goal is to look as natural as possible. Sometimes when I’m acting, I wear even less make-up than I do in normal life," Chastain explained.

After brightening under her eyes with the Hourglass Vanish Seamless Finish Foundation Stick and adding Neen Going Rouge Cheek + Lip Cream to her cheeks, the 47-year-old timeless beauty added a splash of color with an Armani Beauty Lip Power Long Lasting Lipstick.

“If it’s evening and I’m like, ‘I want a big red mouth,’ it just feels so bad ass and French," she emphatically said.

Chastain finished her look with mascara, eyebrow gel, and by contouring to her nose.

30 Celebrity Transformations

These stars look totally different today from when they first became famous.

Gallery Credit: Michele Bird

More From StarCrush