In immortalised human airway epithelial cell lines (including bronchial epithelial cells) and human alveolar epitheliallike cells, GLP-1 receptor agonists reduced epithelial stress and inflammatory signalling, including downregulation of epithelial-derived cytokines, including IL-33 and thymic stromal lymphopoietin (TSLP), both of which are implicated in epithelialmesenchymal crosstalk and fibroblast recruitment in fibrotic lung disease [66,67,68]
When comparing Retatrutide vs Tirzepatide at equivalent dose-adjusted endpoints, the third receptor pathway consistently emerges as the differentiating factor in published research
That extra pathway is one reason researchers are interested in retatrutide, but it is also a reason not to assume its risk profile is identical to tirzepatides
[1] The active fraction turned out to be a three-amino-acid sequence with high affinity for copper(II)
Or worse, it drops a little, then stalls