Cagrilintide (also known as 0833) is an amylin and calcitonin receptor agonist in clinical development for weight management and type-2-diabetes in a fixed-dose combination with semaglutide. Here, we introduce 0174-0839 (0839) as a tool compound for mouse and rat in vivo and in vitro studies of amylin analogues such as cagrilintide. Structurally, 0839 shares 95 % sequence homology with 0833 and contains an identical acylation sidechain. Acute administration of 0839 and 0833 to normal weight rats' dose-dependently reduced food intake to a similar degree. Sub-chronically, 0839 and 0833 had comparable small and transient reducing effects on food intake and body weight in DIO mice, with similar additional add-on effects on top of semaglutide. In DIO rats, sub-chronic administration of 0833 and 0839 profoundly reduced food intake and body weight, and both potentiated semaglutide's effects on food intake and body weight to an equal extended. Both compounds mainly reduced body weight by fat mass reduction and equally improved metabolic parameters. Notably, 0839 is available through Novo Nordisk Compound Sharing, enabling advancement of mode-of-action studies in mice and rats whilst usage of cagrilintide and other amylin analogues in clinical development are restricted due to pharmacovigilance rules.