Proponents of the body positivity (BoPo) movement prominently use social media to promote body appreciation and normalize marginalized bodies. However, companies and social media users have increasingly commodified the movement for self-serving reasons or economic gain. Providing a unique test of the persuasion knowledge model, this experiment examined (a) how the commodification of a prosocial movement can undermine its efficacy and (b) how the symmetry between visual and text-based messaging can influence viewer reactions. Results indicated that body positive posts on Instagram that contained self-promotion or promoted products were viewed as less morally appropriate and were less effective at promoting body appreciation and inclusivity. Practical implications are discussed and a novel boundary condition for the persuasion knowledge model is presented.