Fibroblast growth factor 19 (FGF-19)  is a member of a subfamily of FGFs. It functions as a hormone, regulating bile acid synthesis, with effects on glucose and lipid metabolism.

Circulating FGF-19 plays an important role in maintaining proper bile acid homeostasis. Several pharmacologic studies in  hyperglycaemic, obese animal models have shown that FGF-19 can improve metabolic rate and lower the serum glucose, hepatic triglyceride and cholesterol levels. Like insulin, FGF-19 functions as postprandial hormone to govern hepatic protein synthesis,    glycogen synthesis and gluconeogenesis, but does not stimulate lipogenesis.