Herbs of the Field - Milk Thistle

Milk Thistle is a prickly plant with a distinctive purple flower with white veins. Milk thistle is native to Europe and was brought to America by the early colonist. Milk thistle is considered an invasive weed because it grows in dense patches and outcompetes native plants.

Milk thistle’s active ingredients are flavonoids known as silymarin. Silymarin extracts have antioxidant, antiviral and anti-inflammatory properties. Traditionally Milk thistle has been used to treat liver and gallbladder disorders, promote breast milk production, prevent and treat some cancers, and protect the liver from snake bites, alcohol and other environmental poisons. In addition, Milk thistle is suggested as a dietary supplement for hepatitis, cirrhosis, jaundice, diabetes, and indigestion.

Identification: Native to the Mediterranean region and a member of the asteraceae family, like sunflowers, and daisies. Spiny stems branch at the top, reaching heights of 5 to 10 feet. Leaves are wide and long, about 20 inches, and lobed with white blotches or veins. Leaf edges have spines up to ½ inch long. When crushed, leaves produce a white sap. Flowers are red purple. A small, hard-skinned fruit is brown, spotted, and shiny.   

Harvesting: Milk thistle is best harvested in the fall.  Watch for flowers to dry out, and white or silver seeds appear near the top. Wearing protect clothing and gloves, (remember prickly spines), handle the plant carefully! Cut the head of the plant, leaving two inches of the stalk to hold the plant. Put plant/flower heads in paper bag to dry 5 to 7 days. Remove the seeds. Shake the bag to loosen seeds from the heads. Store seeds in airtight container.

Usage: supplementation, extracts, tea. 150 to 175 mg up to three times daily is considered safe, but higher doses increase risk of side effects.

Cautions:  Milk thistle is generally considered safe. Possible side effects include stomach upset, diarrhea, nausea and vomiting, rash from touching. Should not be used by pregnant or breastfeeding women. Check with physician before using for drug interactions as there are many.