Commercial turmeric products together with its major metabolites curcuminoid and monoterpenoid was claimed to be used as Thai traditional medicine for treatment of several symptoms such as jaundice, allergy, tuberculosis, and metastasis stage cancer for many centuries. However, there is no experiment of the effect of commercial turmeric products against the colon cancer cell-line exist to support the manufacturer claiming yet. In this work, we aim to clarify that 4 on-shelf commercial turmeric products can inhibit the growth of colon cancer cell-line HT-29. The results from our MTT assays revealed that all of the products could inhibit the growth of HT-29 efficiently with IC50 value ranging from 0.15 - 0.4 mg.mL^-1. Moreover, results from our dissolving experiment also suggested that cooking or preparing turmeric or consuming with oil is better than water. From all of the data obtained so far, we would suggest that all turmeric products have a potential effect on colon cancer and thus, may have a benefit to colon cancer patients.