Social media platforms have transformed the relation of pregnant women and new mothers to infant feeding. They are present on these platforms to obtain information or support, share experiences and advocate, including on infant feeding (breastfeeding and formula feeding). Social media platforms have become the repositories of the diversity of their voices which are expressed in multiple ways (words, images and videos). Our analysis focuses on user reactions on Facebook and Instagram (740 comments) following the publication of a blog post written by a Quebec influencer, in partnership with a commercial infant formula company. In a context where breastfeeding is recommended by public health authorities, how is this type of partnership received? What are the voices emerging? How do the voices of these women intersect, respond / oppose / unite? In our study, three types of voices emerge: the voice of « discontent or contestation », « experience » and « approbation ». In conclusion, we suggest that the voices of women, regardless of their infant feeding choice, should be given greater attention from public health authorities and researchers in order to protect physical and emotional well-being.