Blessed Thistle is a plant found primarily in Asia and Europe. Blessed Thistle is also referred to as 'St. Benedict Thistle' and 'Holy Thistle', names that reflect the fact that Blessed Thistle was a popular folk remedy and tonic appreciated by monastic monks in the Middle ages. Blessed Thistle should not be confused with 'Milk Thistle' (also known as Marian, St. Mary's, or Our Lady's Thistle).

In Europe, Blessed Thistle is regarded as an excellent appetite stimulant, and is used in the manufacture of "bitters" to be taken before meals to stimulate stomach and intestinal activity, and aid in digestion and circulation. It is also used in the treatment of constipation and flatulence, and is considered an excellent heart tonic and blood purifier.

The flowers of the Blessed Thistle are commonly brewed to make a slightly bitter, and sweet, tea that has a mild diuretic activity. Blessed Thistle tea is used by contemporary herbalists for the treatment of a variety of liver problems, such as jaundice and hepatitis. Because painful menstruation can involve the liver, Blessed Thistle is a common component of herbal formulas used to relieve menstrual symptoms.

While generally safe, if taken in excess, Blessed Thistle can act as an emetic and lead to nausea and vomiting.