Jessica Biel is going completely natural to spread a message of empowerment to other women. The 37-year-old hit up Instagram Thursday to post a selfie showing her makeup-free and in glasses. Biel is married to Justin Timberlake (who is rumored to be hitting the studios and making music again), and together, they share a son, Silas

Biel is joining Kate Upton’s new #ShareStrong campaign, she explained, writing: "Spreading some self love today with zero filter and zero makeup for my girl @KateUpton. She's on a mission to encourage everyone to feel strong and love themselves *as they are*… and I'm so honored to help spread that message. Take a second to show the real you. Tag someone you admire and pass it on #ShareStrong."

Upton kicked the campaign off by posting a video of herself working out with her daughter Genevieve, whom she shares with husband Justin Verlander. She captioned it: "Through my own personal experiences and my fitness program @strong4mefit, I've met and spoken with some incredibly strong women. I want to open the conversation and give all people a platform to talk about all the struggles and strengths we experience… That's why I created #ShareStrong – a space where we all can be part of the conversation, empower one another, and radiate positivity. I want to hear from YOU!"