Obesity remains a major global health challenge, yet the brain-wide effects of hormones regulating appetite remain incompletely understood. Amylin, co-secreted with insulin by pancreatic β-cells, promotes satiation and is a promising therapeutic target for metabolic disorders. While its receptor distribution is well-characterized, its influence on large-scale neural dynamics is unknown. Here, resting-state fMRI was used to map time-resolved connectivity changes following peripheral amylin administration in wild-type (WT) and receptor activity-modifying protein 1/3 knockout (RAMP1/3 KO) mice. In WT animals, amylin triggered rapid and transient network reconfigurations, engaging canonical satiation hubs such as the area postrema and parabrachial nucleus, and extending to sensory-integrative areas including the inferior colliculus and insular cortex. Early hindbrain responses propagated to hypothalamic, thalamic, and mesolimbic circuits implicated in appetite and reward. These effects, along with amylin-driven modulation of large-scale networks and low-frequency oscillations, were absent in KO mice. The findings position amylin as a potent modulator of distributed brain circuits, offering a framework for targeted obesity treatments.