Blessed thistle (Cnicus benedictus) is a flowering plant with sharp prickles on the stems and leaves. It’s native to the Mediterranean region.

Blessed thistle contains chemicals called tannins, which might help with diarrhea, cough, and swelling.

People use blessed thistle for indigestion, infections, wounds, and many other conditions, but there is no good scientific evidence to support these uses.

Don’t confuse blessed thistle with milk thistle. These are not the same.

There is interest in using blessed thistle for a number of purposes, but there isn’t enough reliable information to say whether it might be helpful.

When taken by mouth: Blessed thistle is commonly consumed in foods. There isn’t enough reliable information to know if blessed thistle is safe to use as medicine or what the side effects might be. In doses greater than 5 grams per cup of tea, blessed thistle might cause stomach upset and vomiting.

When applied to the skin: There isn’t enough reliable information to know if blessed this is safe or what the side effects might be. Blessed thistle might cause an allergic reaction in some people.

Special precautions & warnings:

Pregnancy: Blessed thistle is likely unsafe to use while pregnant. Don’t use it.

Breast-feeding: There isn’t enough reliable information to know if blessed thistle is safe to use when breast-feeding. Stay on the safe side and avoid use.

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 might 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.

Minor

Be watchful with this combination.

Antacids

Antacids are used to decrease stomach acid. Blessed thistle can increase stomach acid. Taking blessed thistle might decrease the effects of antacids.

Medications that decrease stomach acid (H2-blockers)

H2-blockers are used to decrease stomach acid. Blessed thistle can increase stomach acid. Taking blessed thistle might decrease the effects of H2-blockers.

Some common H2-blockers include cimetidine (Tagamet), ranitidine (Zantac), and famotidine (Pepcid).

Medications that decrease stomach acid (Proton pump inhibitors)

Proton pump inhibitors are used to decrease stomach acid. Blessed thistle can increase stomach acid. Taking blessed thistle might decrease the effects of proton pump inhibitors.

Some common proton pump inhibitors include omeprazole (Prilosec), lansoprazole (Prevacid), rabeprazole (Aciphex), pantoprazole (Protonix), and esomeprazole (Nexium).

There are no known interactions with herbs and supplements.

There are no known interactions with foods.

Traditionally, blessed thistle has most often been used by adults as a tea. It’s also used as a liquid extract. Speak with a healthcare provider to find out what type of product and dose might be best for a specific condition.

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.

To learn more about how this article was written, please see the Natural Medicines Comprehensive Database methodology.

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