Liver disease causes around 2 million deaths globally each year, with half due to fibrosis and half due to viral hepatitis and hepatocellular carcinoma. Fibrosis ranks as the 11th leading cause of death worldwide. Egypt has the highest prevalence of hepatitis C virus (HCV) infection, impacting 15%-25% of its rural population. Liver fibrosis results from excessive extracellular matrix protein accumulation, primarily collagen, driven by activated hepatic stellate cells (HSCs). These cells transform into fibrogenic myofibroblast-like cells following liver injury. Emerging antifibrotic therapies aim to reduce fibrogenic cell accumulation and extracellular matrix deposition. Glutaminase (GLS) is an enzyme that converts glutamine, the most abundant amino acid in circulation, into glutamate, releasing ammonia. Humans have four GLS isoforms, with GLS-1 and GLS-2 being significant. Glutamine metabolism influences HSC proliferation and activation, with glutamine converting to α-ketoglutarate for the Krebs cycle and pyrroline-5-carboxylate, which stimulates collagen production. In healthy livers, GLS-2 predominates, while in fibrotic livers, GLS-2 levels decrease, and GLS-1 increases in stromal cells. Inhibiting GLS-1 may reduce HSC proliferation and fibrosis. The selective GLS-1 inhibitor CB-839 is in clinical trials, and the small molecule 968 inhibits GLS-2. These inhibitors help elucidate the roles of GLS isoforms and offer new strategies for targeting glutamine metabolism in liver fibrosis.