Soapwort

Soapwort: what was it used for?

A washing plant first and a medicine second. Dioscorides knew it as the herb “which fullers use for cleaning their wool.” As a medicine Grieve records a decoction for the itch, and the plant as tonic, diaphoretic, and alterative, used in jaundice, rheumatism, skin complaints, and “old venereal complaints,” especially where mercury had failed; it is also sternutatory, provoking sneezing.

Soapwort: what does modern science say?

No European monograph covers it, and the searches of Europe PMC made for this entry found no clinical trial of it as a medicine. Its saponins are now laboratory material: a 2026 study isolated new saponins from the root and found that one of them strongly increased the killing power of saporin, a protein toxin, against breast-cancer cells in culture, as a way of carrying protein drugs into cells.

Soapwort: what did the older authorities say?

Dioscorides, De materia medica (1st century), book 2

Dioscorides calls the root sharp and diuretic, and gives it with honey for disorders of the liver, coughs, and asthma, with other roots to break and pass stones and soften a hard spleen, and as a plaster for leprosy; it induced sneezing, and put up into the nostrils with honey it purged through the mouth. He adds that applied below it brings on menstruation and is an abortifacient. The translators of the modern English version identify his strouthion as soapwort.

Culpeper, The Complete Herbal (1653)

Under “Sopewort, or Bruisewort,” a plant of Venus, Culpeper records that country people bruised the leaves and laid them on cut fingers, hands, or legs to heal them, and that some boasted of it as a diuretic for stone and dropsy and extolled it as an absolute cure of the French pox, better than sarsaparilla or guaiacum; “which, how true it is, I leave others to judge.”