Watercress is edible, exceptionally rich in vitamins and minerals, and has long been valued as a food and medicinal plant. A mildly hot mustardy flavor, very good fresh in salad or on a sandwich or cooked as a pot herb. The seed is ground into a powder and used as a mustard. As a medicinal herb Watercress is used in alternative medicine as an antiscorbutic, depurative, diuretic, expectorant, purgative, hypoglycaemic, odontalgic, stimulant, tonic and stomachic. Culpepper says that the leaves bruised or the juice will free the face from blotches, spots and blemishes, when applied as a lotion.
Further research needs to be done.
Considered a cleansing herb, its high content of vitamin C makes it a remedy that is particularly valuable for chronic illnesses. The plant has been used as a specific in the treatment of tuberculosis. The freshly pressed juice has been used internally and externally in the treatment of chest and kidney complaints. A medicinal poultice of the leaves is said to be an effective treatment for healing glandular tumours or lymphatic swellings and chronic irritations and inflammations of the skin. Applied externally, it has a long-standing reputation as an effective hair tonic, helping to promote the growth of thick hair.