People are injecting peptides to build muscle, trim fat, and reduce inflammation. Does it work?

Synthetic peptides (i.e., made in a lab) for weight loss are injectables called glucagon-like peptide-1 receptor agonists (GLP-1 agonists). They were initially developed for type 2 diabetes.

A novel oral peptide PN-477o with once-daily dosing, high potency and activation of glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic peptide (GIP), and glucagon (GCG) receptors ...