Blessed thistle (Cnicus benedictus) is a flowering plant with sharp prickles that was widely cultivated during the Middle Ages. Shakespeare referenced its use as a cure-all in Much Ado About Nothing, and it is one of the ingredients that flavors Bénédictine liqueur.

In modern herbal medicine, blessed thistle is used in the supportive treatment of gastrointestinal conditions. It contains cnicin, an extremely bitter compound that is thought to stimulate the production of saliva and gastric acid to aid digestion. Blessed thistle has also commonly been used as an herbal galactagogue to promote milk flow.

Blessed thistle seed powder is suitable for tinctures and encapsulation. It should not be confused with milk thistle (Silybum marianum), although both are members of the ragweed family and have the potential to cause allergies.