Pennycress (thlaspi arvense)
Synopsis of pennycress
Pennycress refers primarily to Thlaspi arvense, also known as field pennycress, a wild plant in the Brassicaceae (mustard) family. It is native to Eurasia but has become naturalized across North America. Though better known today as a cover crop and a candidate for biofuel production due to its high oil content, pennycress also holds a lesser-known history in traditional herbal medicine. It contains glucosinolates, flavonoids, saponins, and sulfur compounds, which contribute to its medicinal properties, particularly as a diuretic, detoxifier, and anti-inflammatory agent.
Traditionally, pennycress was used to stimulate urine flow, clear congestion, and support liver and kidney function. It was considered a “blood purifier” in folk medicine, often used to treat skin eruptions, rheumatism, and digestive sluggishness. The whole herb or seeds were made into teas, tinctures, or poultices. Due to its pungency, the plant was also used for bronchial conditions, helping clear mucus and soothe mild respiratory infections.
The seeds have expectorant and emmenagogue (menstruation-stimulating) properties and were traditionally used in small doses to regulate menstrual cycles or relieve urinary tract discomfort. The plant's sulfurous and mustard-like chemistry gives it mild antimicrobial and detoxifying qualities, though it should be used cautiously due to potential irritant effects at high doses.
Historical Use in Medicine
Pennycress has been mentioned in European herbals since the Middle Ages, often under the name Thlaspi or Motherwort of the field. Herbalists like Nicholas Culpeper described its use for inflammations of the kidneys, urine retention, and womb disorders. It was also applied externally to bruises, boils, and swellings.
In folk medicine, particularly in rural parts of Europe and North America, pennycress was used to help “cool the blood”, cleanse toxins, and stimulate digestion. The plant’s sharp, peppery taste was thought to activate internal heat and metabolism, much like other cruciferous herbs such as watercress or mustard greens.
Though never a major herb in Ayurvedic or Traditional Chinese Medicine, its use echoes the common theme in many traditional systems of using bitter, warming herbs to stimulate elimination and detoxify the body.
In recent years, pennycress has gained scientific attention not for its medicinal value but as a biofuel source due to its high seed oil content. However, its traditional medicinal use as a detoxifier and stimulant herb continues to be recognized by herbalists interested in lesser-known wild plants.
pennycress is used to support these body systems
Liver (Traditional)
Products containing pennycress
Nature's Sunshine Immune System
Nature's Sunshine VS-C
Nature's Sunshine VS-C
Nature's Sunshine VS-C® TCM
