Milk Thistle (Silybum marianum)

Traditional use

Milk thistle has been used for over 2,000 years, with its medicinal use documented by Ancient Greek physicians, who prepared it as a tea to treat venomous snake bites. Traditional European herbalists employed milk thistle to address liver and spleen obstructions, jaundice, and gallstones, recognising its role in blood purification and bile stimulation. The plant’s striking white-mottled leaves were once thought to be touched by the Virgin Mary’s milk, giving rise to both its Latin and common names and connecting it symbolically to nourishment and protection.

Clinical discussion

Milk thistle’s key active constituents are flavonolignans, notably silymarin and silybin, concentrated in the seeds. These compounds have been extensively researched for their hepatoprotective (liver-protective) properties. Silymarin is known to:

• Stabilise liver cell membranes

• Promote liver regeneration

• Reduce inflammation and fibrosis

• Protect against liver toxins (e.g., from alcohol, medications, and even Amanita mushroom poisoning)

Herbalists use milk thistle to support liver detoxification, especially when poor liver function manifests as skin conditions (e.g., eczema, acne), digestive issues, hormonal imbalances, or low mood—all of which may result from impaired elimination of metabolic waste or hormone processing.

Other indications include:

• Cirrhosis or fatty liver

• Post-viral hepatitis recovery

• High cholesterol

• Alcohol-related liver damage

In these cases, non-alcoholic preparations (such as capsules or powders) may be preferred, especially in alcohol recovery protocols.

Milk thistle also has traditional use as a galactagogue, helping to increase milk production in breastfeeding mothers, though more evidence is needed to confirm this clinically.

The seeds are mildly bitter with a nutty flavour, making them easy to integrate into daily routines. They can be:

• Ground fresh and added to food (approx. ½ tsp per serving)

• Used in capsules, infusions, or decoctions

• Processed into tinctures (preferably alcohol-free in sensitive cases)

Cultivation/harvesting

Milk thistle is a striking biennial or annual with dramatic purple flowers and spiny leaves. It prefers full sun, well-drained soil, and grows well in both cultivated beds and wilder settings, though it can become invasive if left unchecked.

• Sow seeds in early spring directly into the soil or pots. Plants are hardy but slug-prone, especially when young. Protect seedlings carefully.

• Allow plants to flower and set seed. When seed heads begin to dry and turn brown, it’s time to harvest.

• Wear gloves when handling mature plants, as the sharp spines on the flower heads can easily irritate skin.

• Cut and dry the seed heads, then thresh or shake out the seeds once fully dry. Store in airtight jars away from heat and light.

Milk thistle self-seeds easily, so you may enjoy a long-term stand once established, but monitor its spread if growing near wild areas.