Pirfenidone is an anti-fibrotic drug for the treatment of idiopathic pulmonary fibrosis (IPF). It works by reducing lung fibrosis through downregulation of the production of growth factors and procollagens I and II. Pirfenidone has well-established antifibrotic and anti-inflammatory properties in various in vitro systems and animal models of fibrosis. A number of cell-based studies have shown that pirfenidone reduces fibroblast proliferation, inhibits TGF-β stimulated collagen production and reduces the production of fibrogenic mediators such as TGF-β.