Triphala is an Ayurvedic rasayana formulation reputed for its antitumour activities, and chebulinic acid and chebulagic acid, along with other phenolic acids, have been proposed to be responsible for its effects. In this study, the anti-proliferative activities of these agents were evaluated in colorectal carcinoma cell lines with three phenotypes exposed to several batches of triphala samples with different quantities of chebulinic acid and chebulagic acid. The pro-apoptotic and anti-migratory activities and the probable antitumour mechanisms of the more potent anti-proliferative phytochemical were also investigated. The results demonstrated that chebulinic acid, which exerts potent anti-proliferative, pro-apoptotic and anti-migratory effects, is a key molecule for maintaining the antitumour efficacy of triphala. The antitumour mechanism of chebulinic acid is probably related to the PI3K/AKT and MAPK/ERK pathways. Chebulinic acid is not only a critical component of the anticancer activities of triphala but also a promising natural multi-target antitumour agent with therapeutic potential.