On Thursday, the actress avoided makeup while posting a selfie to Instagram.

"Spreading some self love today with zero filter and zero makeup for my girl @KateUpton," Jessica captioned the of her wearing glasses, her hair messy. "She's on a mission to encourage everyone to feel strong and love themselves *as they are*."

She added, "I'm so honored to help spread that message. Take a second to show the real you."

The "Sinner" star encouraged others to tag a friend and do the same.

Around the same time Jessica was posting her tribute, Kate said her mission, called Share Strong, is meant to inspire people to post photos and videos that "radiate positivity."

© Joe Scarnici / Getty Images for Copper Fit Kate Upton promotes Copper Fit at Dick's Sporting Goods in El Segundo, California, on Jan. 9, 2019.

"It's to spread positivity and inspiration by creating a community that talks about encouraging, empowering stories and self motivation," Kate said in a video.

Not long after Jessica posted her "Share Strong" makeup-free photo, her husband, Justin Timberlake, commented, "I like you better with no makeup on."

Jessica wasn't the only celeb participating in Kate's campaign. Comedian Whitney Cummings posted a video to her Instagram Story and Lady Antebellum singer Hillary Scott shared a story of "self care."

"When I think about what and who motivates me it's these three little girls and their daddy," Hillary captioned snapshots of her children. "My goals entail doing something daily to strengthen my spiritual, mental, and physical body. MOVE my body(boxing, yoga). Listen and read things that MOVE my heart and mind(time with God, reading, podcasts, listening to music) so I am set up better to act out of a place of love and strength, not fear and insecurity. True self-care is healthy and not selfish. I've learned from experience(the hard way!)"