Bruno Vonargburg is very thorough in his description of the chemical constituent history of Blessed Thistle: “The research of the chemical substances of Blessed Thistle begin in 1837. There is a high content of bitter principles, the so-called cnicin.  The bitterness at 1/1800 is an 1800 dilution where one can still taste the bitterness.  Other chemicals are Benedictia, Cnicinolid, Arcticitrol, Arctiing etheric oil with Fenchon, Citral, Cimmonaldehyde and paraffin, further polyencer and oleanol, mucus and tannins, polystyrene, calcium, magnesium, and Vitamin B.”

The essential oil of Blessed Thistle is described by R. Vanhoelon-Fastre of the Pharmaceutical Institute of the Free University of Brussels as an antibiotic effect.  The essential material influences the stomach secretions, works as an appetite stimulant, and furthers the colon action.  It increases the pancreatic secretions, releases cramps of the gallbladder/liver region.  It furthers the peristaltic movement of the stomach and strengthens the entire organism. 

Bitter herbs keep their importance in medicine as a tonic.  There has been 30 different uses of Blessed Thistle as a tonic since the time of Hippocrates.

Its description from the Flora website describes the chemical actions and constituents as follows: “Certain bitter flavonoids found in the leaves, stems, and barks of many plants, particularly the oligomeric proanthocyanidins (OPCs), have indeed been shown to strengthen the walls of blood vessels and capillaries thereby improving overall blood circulation.  OPCs have also been shown to bind to collagen and prevent its degradation by enzymes and free radicals and aid in the repair of damaged collagen and elastin.  Blessed thistle extracts also have anti-bacterial activity.  Research on blessed thistle herb has demonstrated antibiotic properties for: 1) cnicin, 2) the essential oil, and 3) the polyacetylenes contained in the herb.  The essential oil has bacteriostatic action against Staphylococcus aureus, S. faecalis, but not E. Coli. Research on blessed thistle has demonstrated that cnicin has considerable activity for stimulating cellular regeneration, detoxification and cleansing.  The lignans arctiin and arctigenin, also found in burdock seed, are also noted for this activity and are platelets activating factor (PAF) antagonists and anti-HIV as well.  Cnicin also has anti-inflammatory activity.”

Continuing with this description: “Active Ingredients: Blessed thistle herb and flowers contain: Bitter substances of the sesquiterpen lactone type, probably occurring in glycosidic form; the principal active ingredient (0.2-0.7%) of the not-too-old dried plant material is a bitter tasting compound called cnicin, a sesquiterpene lactone or germacranolide isolated all the way back in 1837.  The seed contains lignan lactones, such as trachelogenin, that also contribute to the bitterness of the drug.  Lignans are phyto-estrogen precursors for the key mammalian lignans: enterolactone and enterodiol that are present in humans and animals.  The plant also contains: up to 0.3% essential oil which includes n-paraffin (C-9-C13), aromatic aldehydes (cinnamaldehyde, benzaidehyde, cuminaldehyde); phenylpropanes; benzoic acid; monoterpenes (citronellol, fenchone, p-cymene, citral, and others; and flavonoids.