-Tetrahydrocannabinol (THC) and cannabidiol(CBD) are phytocannabinoids that have a potential impact in cancer treatments.Studies have shown that certain cannabinoids cause cancer cells to die, but only with selective concentrations, which have not been well documented. The first study of this thesis was to determine the exact concentration of CBD and THC needed to kill human MCF-7 breast cancer cells, rather than creating mass multiplication leading to more growth of the cancer. To conduct this experiment, cell culture was performed with a MCF-7 breast cancer cell line. The treatment groups were treated with CBD or THC at varying concentrations including 0.1, 1, 10 and 100 µM. Observations were made by using tetrazolium dye (MTT assay), whi...