Liver detoxification is the process by which the liver metabolizes or eliminates harmful substances, making them less harmful to the body. Proper functioning of the detoxification mechanism is vital for our general health. A malfunctioning detox system can negatively affect liver, bile and heart health and increase the risk of cancer. The status of the genes encoding the enzymes involved in liver detoxification also determines the activity of these enzymes. Thanks to the determination of phenotype on genotype, nutritional and vitamin supplements that will support liver detoxification, also foods and chemicals that should be avoided can be determined.