Milk thistle is a popular liver detox supplement. It's full of powerful antioxidant flavonoids that provide protective support for the liver, spleen and kidneys. Taken from the seed of a flowering herb that's closely related to daisies and ragweed, milk thistle (Silybum marianum) has been used for thousands of years as an herbal tonic to lend support to liver health. The importance of your liver can't be overstated. An essential organ, your liver works hard to cleanse your blood of toxins at an astounding rate of 1 quart per minute to keep your body healthy and functioning. That's why it's important to nourish your liver with milk thistle. Milk thistle detoxifies the liver with the help of the flavonoid silymarin, which works to boost the strength of the outer membrane of liver cells, making them more resistant to toxins.