Supplement guide

Blessed Thistle - Cnicus Benedictus - Oral

Learn about the uses, forms, amounts, and precautions for Blessed Thistle - Cnicus Benedictus - Oral. This guide brings the relevant conditions together so you can see who the information covers, how preparations differ, and what to consider before use.

Prepared by Dr. Edward M.Kim, PharmD · Clinical Director, SupplementSafety editorial team · Sources and editorial method

First released · Updated · View changes

What is it used for?

  • (Traditionally) used in Herbal Medicine (as a digestive tonic and bitter) to increase appetite and (as a stomachic) to aid digestion [Source note 2].

  • (Traditionally) used in Herbal Medicine to help relieve indigestion/dyspepsia [Source note 3].

  • Traditionally used in Herbal Medicine (as an expectorant) to help relieve cold symptoms such as excessive mucus build up (excessive catarrh) [Source note 4].

  • The above uses can be combined on the product label if from the same traditional or non-traditional system of medicine (e.g., Traditionally used in Herbal Medicine to help relieve indigestion and cold symptoms such as excessive mucus build up).

  • For multi-ingredient products:

    • To prevent the product from being represented as a "traditional medicine", any indicated traditional use claim must refer to the specific active ingredient(s) and recognized traditional system of medicine from which the claim originates when 1) both traditional and modern claims are present or 2) when claims originate from multiple systems of traditional medicine (e.g., Blessed thistle is traditionally used in Herbal Medicine to help relieve indigestion).

    • When ALL of the active ingredients (MIs) in the product are used within the SAME identified system of traditional medicine AND the product makes ONLY traditional claims, listing of MIs in the traditional claim(s) is not required.

Who does this guide cover?

Adults 18 years and older

How is it taken?

Oral

Which forms are covered?

this reference excludes foods or food-like dosage forms as indicated in the Compendium of references Guidance Document.

Quantities

Methods of preparation: Powdered, Non-Standardized Ethanolic Extracts (Dry extract, Tincture, Fluid extract)

0.6 - 6 grams of dried herb tops, per day [Source note 5].

Methods of preparation: Dry*, Non-Standardized Aqueous Extracts (Dry extract, Decoction, Decoction concentrate, Infusion, Infusion concentrate)

4 - 9 grams of dried herb tops, per day [Source note 6].

*Note: Dried herb tops should be prepared as an infusion or decoction by consumers prior to use (see direction for use) [Source note 7].

How is it used?

Loose dosage form (for infusion/decoction)*

Place [insert volume to be measured by consumer, e.g., X teaspoons] of dried herb tops in [insert the volume of water, e.g., ½ cup (125 mL)] of boiling/cold water. Infuse for [e.g., 5-15 minutes]/Bring to a boil and let simmer for [e.g., 10-20 minutes]. Strain and drink.

*Note: This direction of use statement can be modified on the label provided that it gives clear instructions to consumers.

How long is it used?

The reference does not require an additional label statement in this section. This does not establish an absence of risk.

Warnings and precautions

  • Ask a healthcare professional if symptoms persist or worsen.

  • Ask a healthcare professional before use if you are breastfeeding.

When should it be avoided?

Do not use if you are pregnant [Source note 8].

Possible side effects

Stop use if hypersensitivity/allergy occurs [Source note 9].

Storage

Must be established in accordance with the requirements described in the applicable product regulations.

Preparation details

Ingredient identity, preparation requirements, and other details that define the scope of this guide.

Ingredients and preparations
Table 1. Proper name(s), Common name(s), Source information
Proper name(s)Common name(s)Source information / Source material(s)Source information / Part(s)Source information / Preparation(s)
Cnicus benedictus
  • Blessed thistle
  • Holy thistle
Cnicus benedictusHerb topsDry

References: Proper name: USDA 2024; Common names: Gardner and McGuffin 2013; Bradley 1992; Felter and Lloyd 1983; Source information: Williamson 2003; Bradley 1992.

Other ingredients

Must be chosen from the current source ingredient database and must meet the limitations outlined in the database.

Preparation and quality requirements
  • The finished product specifications must be established in accordance with the requirements described in the source authority source’s product quality guidance.

  • The active ingredient must comply with the requirements outlined in the source ingredient database.

Guide change history

Updates to this SupplementSafety.org guide.

  1. Minor updates

    Updated guide wording, organization, and source presentation. Added our editorial change history.

  2. Initial release

    Initial SupplementSafety.org guide prepared from source reference material.

Validation: Not yet completed. Editorial updates do not constitute clinical validation.

Sources

Source information

This guide organizes source material about uses, preparations, amounts, and precautions. Read the conditions alongside each statement; the information may apply only to particular preparations or populations.

The source document includes supporting references. We have not independently summarized or assessed every cited study for this guide.

Source document version
January 30, 2026
Source captured
Aug 15, 2026
Editorial work
Editorial preparation. Independent clinical review has not been recorded for this guide.

Full citations are available through the link above. Verification is required to open them; reading this guide does not require verification.

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