Milk thistle: silymarin and botanical extracts
Milk thistle is a Mediterranean plant with a long history of use. Supplements can contain whole plant material or extracts, often referring to silymarin. Understanding these terms helps compare products.
What is milk thistle?
Silybum marianum belongs to the Asteraceae family. It has spiny leaves with white veins and purple flowers. The part used in many preparations is the fruit, commonly described as the seed. [1] [2]
What is silymarin?
Silymarin is a group of botanical compounds, mainly flavonolignans, including silybin, silychristin and silydianin. A label reference to silymarin describes the extract's composition or standardisation. [2]
These compounds have been studied in laboratory and animal models for redox mechanisms and interactions with liver cells. Research under specific experimental conditions should be distinguished from the clinical use of a product in people.
Why is it traditionally associated with the liver?
The European Medicines Agency has assessed specific milk thistle herbal medicinal preparations on the basis of traditional use for mild digestive complaints and support of liver function after serious conditions have been excluded by a doctor. That assessment concerns the particular preparations and their directions. [1]
The liver participates in metabolism and the processing of many substances. Diagnosed liver disease, abnormal tests or persistent symptoms require medical follow-up when choosing products. [3]
Powder, extract and standardisation
- Whole-herb powder: milled plant material retaining its natural composition.
- Extract: selected components obtained by extraction.
- Standardised extract: an extract with a declared level of particular compounds, such as a silymarin percentage.
Milligrams of plant powder, extract and silymarin describe different things. [1] [3]
A label-reading example
An extract stated as 200mg, standardised to 80% silymarin, corresponds arithmetically to 160mg silymarin. This illustrates label reading, not a recommended dose. Check the plant part, daily serving, extract ratio and other ingredients as well.
Food and precautions
Milk thistle has been used as a herb and food in some traditions. A silymarin extract, however, is a specific preparation rather than an ordinary food group. [2]
Digestive discomfort or allergic reactions can occur, particularly with an allergy to Asteraceae plants. Medication use, liver disease, pregnancy and breastfeeding require individual advice. Persistent digestive symptoms should be assessed. [1] [3]
Scientific sources
- European Medicines Agency — Silybi mariani fructus
- NIDDK / LiverTox — Milk Thistle
- NCCIH — Milk Thistle
Informational article. Supplement choices should reflect your diet, needs and health history. For diagnosed deficiency, chronic illness, medication use, pregnancy or breastfeeding, consult a healthcare professional.
