AIM: To elucidate the effect of inhibiting follistatin-like 1 on liver fibrosis and activation of hepatic stellate cells in mice. METHODS: We generated a follistatin-like 1 neutralizing antibody that can inhibit TGF-β 1-induced expression of collagen1α1 in primary mouse liver fibroblasts. All of the mice in our study were induced with carbon tetrachloride and thioacetamide. In addition, primary hepatic stellate cells from mice were isolated from fresh livers using density gradient separation. The degree and extent of fibrosis in mouse livers from the different groups were evaluated by Sirius Red and Masson staining. The effect of the follistatin-like 1 neutralizing antibody on proliferation and migration of hepatic stellate cells was detected using CCK-8 and Transwell assays, respectively. RESULTS: . CONCLUSIONS: Inhibiting follistatin-like 1 attenuates liver fibrosis and causes a delay in hepatic stellate cell activation. The effect of follistatin-like 1 on liver fibrosis is mainly attributed to its role in regulating TGF-beta signaling.