Technology may facilitate health and wellbeing consumer engagement. When there is scant public health provision and sociocultural norms marginalise consumers stigmatised from cancer, we reveal how a brands' corporate social media campaign can support vulnerable consumers with resource constraints. Drawing from a transformative consumer research lens, we investigate five years of computer-mediated communications facilitated by the Indian brand Dabur Vatika. Through a grounded theory and an abductive reasoning approach, we unveil how vulnerable consumers directly or indirectly affected by cancer leverage brand's social media to replenish resources. First, we identify how vulnerable consumers engage to replenish depleted emotional and social support resources. We further expand consumer engagement scholarship by offering a preliminary definition of "vulnerable consumer engagement". Second, we provide a nascent classification of vulnerable consumers in a consumer-producer role, Principal Vulnerable Consumers and Associate Vulnerable Consumers, distinguished by their proximity to the vulnerable context. Lastly, we reveal how brands may perform a transformative role, to replenish social, emotional and operant resources at micro level through the engagement of vulnerable consumers with corporate social media. This insight is informative for policymakers, advertising practitioners and transformative consumer research academics.