Grind milk thistle seed in a coffee grinder or spice mill, and add the ground seeds to shakes or cereals. Or encapsulate the ground seed, if preferred. To prepare milk thistle tea, add one cup of boiling water to one teaspoon of ground seeds, and steep for 15 minutes.

The ground seeds can also be prepared as a tincture using a menstruum of 50% alcohol and 50% water (or 100 proof vodka).

The whole seeds can be toasted and added to salads, breads and cereals.

Milk thistle seed has been extensively researched for its protective effects on the liver. While formulations with concentrated levels of silymarin (70 to 80%) are being studied as a treatment for various liver problems (especially in Europe), the whole seed, with its much lower silymarin levels, is used as a liver tonic, to "support healthy liver function" and overall well-being. Chronic drug and alcohol abusers also use milk thistle as a supporting herb.

The Botanical Safety Handbook* classifies milk thistle seed as:
Class: 1: Herbs which can be safely consumed when used appropriately.
Per the German Commission E Monograph** for milk thistle seed, there are no known contraindications, side effects or drug interactions.

*Michael McGuffin, ed., American Herbal Products Association's Botanical Safety Handbook, (New York: CRC Press, 1997)

**Mark Blumenthal, ed., The Complete German Commission E Monographs, (Austin TX: Integrative Medicine Communications, 1998)