In detail

Silymarin is a mixture of flavonolignans, including silybin A and B, silychristin, and silydianin. The familiar 80% milk thistle extract is usually a UV family total. Silybin is one component, and an HPLC silybin result will not equal the UV silymarin percentage.

For labels that name silymarin, a UV specification may be sufficient. For labels or studies that name silybin, ask for the HPLC figure and the method. The two numbers should not be used interchangeably in a specification or a marketing claim.

Why it matters to a buyer

  • Milk thistle is one of the most common botanicals where UV and HPLC numbers are confused.
  • The distinction affects label wording and cost.
  • A specification should state which marker and method the claim relies on.

What to ask a supplier

01

Is the 80% figure silymarin by UV or silybin by HPLC?

02

What is the silybin content and method if our label names silybin?

03

Can you provide both values on the COA?

Cite this page

Rainwood Botanical. "Silymarin." Botanical extract glossary, October 2026. https://ingredients.rainwoodbio.com/resources/glossary/silymarin/