St. Mary's Thistle is the common name for Milk Thistle (Silybum marianum). They are the same plant. This product is the whole dried seed (fruit) of the plant, which is traditionally used in herbalism.
In traditional European herbalism, Milk Thistle has been used for centuries as a 'liver tonic' to support liver health and aid digestion. Its properties are linked to a compound complex called Silymarin. This product is sold as a food-grade herb only.
The whole seeds are extremely hard and must be ground into a powder before use. A simple tea infusion is not effective. Once ground, the powder can be steeped in hot water to make a tea, or added to smoothies, muesli, or juices.
You can, but it is not recommended. The seeds are very tough, and your body cannot break them down to access the beneficial compounds. You must grind them in a coffee or spice grinder first.
Silymarin is not a single substance, but a group of active compounds (flavonolignans) found inside the milk thistle seed. It is the component most studied and associated with the herb's traditional use.
You should not take it if you have an allergy to the Asteraceae (daisy) family, which includes ragweed, chamomile, and marigolds. As it can affect the liver and hormones, consult a healthcare professional before use if you are pregnant, breastfeeding, or on any medication.
