Milk thistle
Silybum marianum (L.) Gaertn.Asteraceae // fruit (seed-like achenes)
Overview
Plant parts
fruit (seed-like achenes)
Known constituents
silymarin flavonolignans, silybin
Research corpus coverage
Chemistry notes
- CHEMISTRY: Relevant reported constituents include silymarin flavonolignans; silybin; constituent presence alone does not establish clinical efficacy.
Uses & Evidence
Traditional / historical use
Documented traditional use — not a claim of established efficacy.
TRADITIONAL: Milk thistle has been used for liver and gallbladder complaints; this records historical/traditional use and does not establish efficacy.
MODERATE · evidence synthesis/fact sheet · NCCIH Herbs at a Glance
Modern evidence
EVIDENCE: For the major use set (liver and gallbladder complaints), the evidence assessment is limited/mixed: Limited/mixed systematic reviews for chronic liver disease; no reliable proof of preventing drug-induced liver injury.
MODERATE · systematic review/meta-analysis · NCCIH Herbs at a Glance
Mixed findings, product heterogeneity, or indirect evidence are preserved in the detailed profile.
Preparation
Forms used traditionally
A listed form does not imply it suits every plant part, or that one preparation is interchangeable with another — see the plant’s own notes below.
PREPARATION: The medicinal material is fruit (seed-like achenes); traditional and modern forms include infusion/tea, tincture, powder/capsule, extract. No dose or potency is specified.
MODERATE · regulatory monograph · EMA European Union herbal monographs and list entries
Preparation-specific evidence should not be generalized across extracts, teas, oils, or whole herb.
Safety
Cats & dogs
- Caution
High doses of silibinin may increase bilirubin levels and liver enzymes; the clinical significance of CYP450 effects is unclear.
Intrinsic toxicity · OTHER · milk-thistle seeds, derivatives, or silymarin/silibinin preparation · MODERATE · veterinary_manual · Herbal Medicine in Veterinary Patients - Therapeutics
Additional safety notes (general, unstructured)
Free-text safety notes carried from their source — not broken out by species, route, or hazard type, and not equivalent to the structured records above. Each note names the kind of source it came from.
SAFETY: Major issues include Usually mild GI effects; Asteraceae allergy. Contraindications/cautions include Asteraceae allergy.
MODERATE · observational/case series and expert review · LiverTox: Herbal and Dietary Supplements
SAFETY: Clinically relevant interaction concerns include Possible CYP or transporter effects, but clinical importance is uncertain.
MODERATE · observational/case series and expert review · LiverTox: Herbal and Dietary Supplements
Some interactions are theoretical or based on case reports/pharmacokinetics rather than outcome trials.
SAFETY: Pregnancy/lactation reference: Insufficient pregnancy/lactation evidence.
MODERATE · regulatory monograph or evidence synthesis · NCCIH Herbs at a Glance
Absence of evidence is not evidence of safety.
High doses of silibinin may increase bilirubin levels and liver enzymes; the clinical significance of CYP450 effects is unclear.
MODERATE · veterinary_manual · Herbal Medicine in Veterinary Patients - Therapeutics
Species and route were not specified.
Preparation × species risk matrix
Unknown means insufficient evidence was located — not that a form is safe.
Cats
- tinctureCaution
- whole herbCaution
- concentrated extractUnknown
- essential oilUnknown
- glyceriteUnknown
- infused oilUnknown
- salveUnknown
- smoke/combustionUnknown
- tea/infusionUnknown
Dogs
- tinctureCaution
- whole herbCaution
- concentrated extractUnknown
- essential oilUnknown
- glyceriteUnknown
- infused oilUnknown
- salveUnknown
- smoke/combustionUnknown
- tea/infusionUnknown
Identity
- Synonym
GBIF resolves Carduus marianus L. as a synonym of Silybum marianum. The older name still appears in herbal and taxonomic literature.
HIGH · GBIF Species Match API
Botanical synonym
Carduus marianus L.
Taxonomic identity note
- Milk thistle is treated here as Silybum marianum (L.) Gaertn. in the family Asteraceae; recorded older names include Carduus marianus L..
Sources
Research records are source-linked but may not yet be editorially reviewed.
- NCCIH Herbs at a Glance3 claims
NCCIH fact sheet
NIH LiverTox monograph
veterinary_manual
- Plants of the World Online1 claim
botanical taxonomy database
EMA monograph
WHO monograph
- GBIF Species Match API1 claim
authoritative taxonomic database