GLP-1–Induced Weight Loss and the Face: Anatomical Mechanisms and Rationale for Collagen-Stimulating and Volumizing Aesthetic Treatments

BACKGROUND: Glucagon-like peptide-1 (GLP-1) receptor agonists have transformed medical weight-loss therapy and have been associated with characteristic facial changes, including hollowing, skin laxity, and contour alterations that may accentuate pre-existing signs of aging. OBJECTIVE: To review the anatomical basis of facial changes after GLP-1-associated weight loss and provide an evidence-based rationale for injectable aesthetic treatment using collagen-stimulating agents and hyaluronic acid (HA) fillers. METHODS: A narrative review was conducted focusing on region-specific facial aging anatomy, fat-compartment behavior, skeletal remodeling, soft-tissue mechanics, and skin changes associated with rapid weight loss. These findings were integrated with current international consensus recommendations for patients undergoing medication-derived weight loss. RESULTS: Facial changes after medical weight loss involve multiple structural layers, including deflation of superficial fat compartments, loss of deep support, skeletal resorption, and increased skin laxity. Midfacial volume loss seems to occur mainly in superficial fat compartments, contributing to contour flattening and more pronounced transition lines. These changes support a treatment strategy combining early collagen stimulation with targeted HA filler placement to address tissue quality, support, and volume loss. CONCLUSION: Effective management of the medical weight-loss face requires an anatomically informed, multimodal approach using early biostimulation and selective HA-based structural restoration.