Body functionality refers to the full range of the body’s abilities (Alleva, Martijn, et al., 2015). With its holistic design and desire to represent the wealth of the body, it has become an innovative field that could be promising in order to improve body dissatisfaction and overcome the limitations encountered in research relating to body image. However, just a few studies havebeen conducted and its benefits have not yet been evaluated in France. This study tested the effectiveness of an online intervention program targeting body functionality. This program combines two tools developed in the field of body functionality: the media campaigns "#jointhemovement", "This Girl Can" and "This Girl Can, Me Again" and the writing tasks from the Expand Your Horizon program. 104 volunteer women aged from 18 to 30 years old were randomly assigned to two interventions, an experimental one targeting functionality and a control one targeting decentration, which involves turning attention away from the body to focus on creativity. Assessment of body functionality appreciation, state body satisfaction, body appreciation, social comparison, and intention to engage in physical activity were measured using questionnaires at pre-test, post-test at the end of the intervention, and 10 days follow-up. The results of this study show that the body functionality program showed a better improvement in body functionality appreciation, state body satisfaction, and social comparison, at post-test and follow-up than compared to the control group. No significant differences in body appreciation and intention to engage in physical activity were observed. The results and limitations of this study will be discussed. Ideas for program improvement and therapeutic perspectives will also be discussed, such as the inclusion of behavioral tasks or the value of conducting this program in a group setting.