Skip navigation

Blessed thistle


What is it?

Blessed thistle is a plant. People use the flowering tops, leaves, and upper stems to make medicine. Blessed thistle was commonly used during the Middle Ages to treat the bubonic plague and as a tonic for monks.

Today, blessed thistle is prepared as a tea and used for loss of appetite and indigestion; and to treat colds, cough, fever, bacterial infections, and diarrhea. It is also used as a diuretic for increasing urine output, and for promoting the flow of breast milk in new mothers.

Some people soak gauze in blessed thistle and apply it to the skin for treating boils, wounds, and ulcers.

In manufacturing, blessed thistle is used as a flavoring in alcoholic beverages.

Don’t confuse blessed thistle with milk thistle (Silybum marianum).

How effective is it?

Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, Ineffective, and Insufficient Evidence to Rate.

The effectiveness ratings for BLESSED THISTLE are as follows:

Insufficient evidence to rate effectiveness for...

  • Diarrhea.
  • Coughs.
  • Infections.
  • Boils.
  • Wounds.
  • Promoting milk flow in breast-feeding mothers.
  • Promoting urine flow.
  • Other conditions.
More evidence is needed to rate the effectiveness of blessed thistle for these uses.

How does it work?

Return to top
Blessed thistle contains tannins which might help diarrhea, coughs, and inflammation. However, there isn't enough information to know how well blessed thistle might work for many of its uses.

Are there safety concerns?

Return to top
Blessed thistle might be safe for most people. In high doses, such as more than 5 grams per cup of tea, blessed thistle can cause stomach irritation and vomiting.

Special precautions & warnings:

Pregnancy and breast-feeding: Don’t take blessed thistle by mouth if you are pregnant. There is some evidence that it might not be safe during pregnancy. It’s also best to avoid blessed thistle if you are breast-feeding. Not enough is known about the safety of this product.

Intestinal problems, such as infections, Crohn's disease, and other inflammatory conditions: Don’t take blessed thistle if you have any of these conditions. It might irritate the stomach and intestines.

Allergy to ragweed and related plants: Blessed thistle may cause an allergic reaction in people who are sensitive to the Asteraceae/Compositae family. Members of this family include ragweed, chrysanthemums, marigolds, daisies, and many others. If you have allergies, be sure to check with your healthcare provider before taking blessed thistle.

Are there interactions with medications?

Return to top

Minor

Be watchful with this combination.

Antacids
Antacids are used to decrease stomach acid. Blessed thistle may increase stomach acid. By increasing stomach acid, blessed thistle might decrease the effectiveness of antacids.

Some antacids include calcium carbonate (Tums, others), dihydroxyaluminum sodium carbonate (Rolaids, others), magaldrate (Riopan), magnesium sulfate (Bilagog), aluminum hydroxide (Amphojel), and others.

Medications that decrease stomach acid (H2-blockers)
Blessed thistle might increase stomach acid. By increasing stomach acid, blessed thistle might decrease the effectiveness of some medications that decrease stomach acid, called H2-blockers.

Some medications that decrease stomach acid include cimetidine (Tagamet), ranitidine (Zantac), nizatidine (Axid), and famotidine (Pepcid).

Medications that decrease stomach acid (Proton pump inhibitors)
Blessed thistle might increase stomach acid. By increasing stomach acid, blessed thistle might decrease the effectiveness of medications that are used to decrease stomach acid, called proton pump inhibitors.

Some medications that decrease stomach acid include omeprazole (Prilosec), lansoprazole (Prevacid), rabeprazole (Aciphex), pantoprazole (Protonix), and esomeprazole (Nexium).

Are there interactions with herbs and supplements?

Return to top
There are no known interactions with herbs and supplements.

Are there interactions with foods?

Return to top
There are no known interactions with foods.

What dose is used?

Return to top
The appropriate dose of blessed thistle depends on several factors such as the user’s age, health, and several other conditions. At this time there is not enough scientific information to determine an appropriate range of doses for blessed thistle. Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult your pharmacist or physician or other healthcare professional before using.

Other names

Return to top
Carbenia Benedicta, Cardo Bendito, Cardo Santo, Carduus, Carduus Benedictus, Chardon Béni, Chardon Bénit, Chardon Marbré, Cnici Benedicti Herba, Cnicus, Cnicus benedictus, Holy Thistle, Safran Sauvage, Spotted Thistle, St. Benedict Thistle.

Methodology

Return to top
To learn more about how this article was written, please see the Natural Medicines Comprehensive Database methodology.methodology (http://www.nlm.nih.gov/medlineplus/druginfo/natural/methodology.html).

References

Return to top
To see all references for the Blessed thistle page, please go to http://www.nlm.nih.gov/medlineplus/druginfo/natural/94.html.

  1. Duke JA. Green Pharmacy. Emmaus, PA: Rodale Press;1997:507.
  2. Yang L, Lin S, Yang T, and et al. Synthesis of anti-HIV activity of dibenzylbutyrolactone lignans. Bioorg Med Chem Lett 1996;6:941-944.
  3. Maeda Y and Mitsuya H. Antiretroviral chemotherapy against AIDS. Med Biol Environ 1995;23:267-278.
  4. Recio M, Rios J, and Villar A. Antimicrobial activity of selected plants employed in the Spanish Mediterranean area. Part II. Phytother Res 1989;3:77-80.
  5. Perez C and Anesini C. Inhibition of Pseudomonas aeruginosa by Argentinean medicinal plants. Fitoterapia 1994;65:169-172.
  6. Vanhaelen M and Vanhaelen-Fastre R. Lactonic lignans from Cnicus benedictus. Phytochemistry 1975;14:2709.
  7. Ulbelen A and Berkan T. Triterpenic and steroidal compounds of Cnicus benedictus. Planta Medica 1977;31:375-377.
  8. Kataria H. Phytochemical investigation of medicinal plant Cnicus wallichii and Cnicus benedictus L. Asian J Chem 1995;7:227-228.
  9. Vanhaelen-Fastre R. [Polyacetylen compounds from Cnicus benedictus]. Planta Medica 1974;25:47-59.
  10. Mascolo N, Autore G, Caspasso F, and et al. Biological screening of Italian medicinal plants for antiinflammatory activity. Phytother Res 1987;1:28-31.
  1. Pfeiffer K, Trumm S, Eich E, and et al. HIV-1 integrase as a target for anti-HIV drugs. Arch STD/HIV Res 1999;6:27-33.
  2. Umehara K, Sugawa A, Kuroyanagi M, and et al. Studies on the differentiation-inducers from Arctium fructus. Chem Pharm Bull 1993;41:1774-1779.
  3. Ryu SY, Ahn JW, Kang YH, and et al. Antiproliferative effect of arctigenin and arctiin. Arch Pharm Res 1995;18:462-463.
  4. Moritani S, Nomura M, Takeda Y, and et al. Cytotoxic components of Bardanae Fructus (Goboshi). Biol Pharm Bull 1996;19:1515-1517.
  5. Cobb E. Antineoplastic agent from Cnicus benedictus. Patent Brit 1973;335:181.
  6. Vanhaelen-Fastre, R. and Vanhaelen, M. [Antibiotic and cytotoxic activity of cnicin and of its hydrolysis products. Chemical structure - biological activity relationship (author's transl)]. Planta Med 1976;29:179-189. View abstract.
  7. Barrero, A. F., Oltra, J. E., Morales, V., Alvarez, M., and Rodriguez-Garcia, I. Biomimetic cyclization of cnicin to malacitanolide, a cytotoxic eudesmanolide from Centaurea malacitana. J Nat Prod. 1997;60:1034-1035. View abstract.
  8. Eich, E., Pertz, H., Kaloga, M., Schulz, J., Fesen, M. R., Mazumder, A., and Pommier, Y. (-)-Arctigenin as a lead structure for inhibitors of human immunodeficiency virus type-1 integrase. J Med Chem 1-5-1996;39:86-95. View abstract.
  9. Nose, M., Fujimoto, T., Nishibe, S., and Ogihara, Y. Structural transformation of lignan compounds in rat gastrointestinal tract; II. Serum concentration of lignans and their metabolites. Planta Med 1993;59:131-134. View abstract.
  10. Hirano, T., Gotoh, M., and Oka, K. Natural flavonoids and lignans are potent cytostatic agents against human leukemic HL-60 cells. Life Sci 1994;55:1061-1069. View abstract.
  11. Schimmer, O., Kruger, A., Paulini, H., and Haefele, F. An evaluation of 55 commercial plant extracts in the Ames mutagenicity test. Pharmazie 1994;49:448-451. View abstract.
  12. Perez, C. and Anesini, C. In vitro antibacterial activity of Argentine folk medicinal plants against Salmonella typhi. J Ethnopharmacol 1994;44:41-46. View abstract.
  13. Goggelmann, W. and Schimmer, O. Mutagenicity testing of beta-asarone and commercial calamus drugs with Salmonella typhimurium. Mutat.Res 1983;121(3-4):191-194. View abstract.
  14. Vanhaelen-Fastre, R. [Constitution and antibiotical properties of the essential oil of Cnicus benedictus (author's transl)]. Planta Med 1973;24:165-175. View abstract.
  15. Vanhaelen-Fastre, R. [Antibiotic and cytotoxic activity of cnicin isolated from Cnicus benedictus L]. J Pharm Belg. 1972;27:683-688. View abstract.
  16. Schneider, G. and Lachner, I. [Analysis and action of cnicin]. Planta Med 1987;53:247-251. View abstract.
  17. May, G. and Willuhn, G. [Antiviral effect of aqueous plant extracts in tissue culture]. Arzneimittelforschung 1978;28:1-7. View abstract.
  18. Electronic Code of Federal Regulations. Title 21. Part 182 -- Substances Generally Recognized As Safe. Available at: http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr&sid= 786bafc6f6343634fbf79fcdca7061e1&rgn=div5&view= text&node=21:3.0.1.1.13&idno=21
  19. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  20. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
  21. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics. 2nd ed. New York, NY: John Wiley & Sons, 1996.
  22. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.
Show more references
Show fewer references
Last reviewed - 04/03/2012




Page last updated: 10 December 2014