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Herb library · Herb · Saponaria officinalis

Soapwort

A pink-flowered roadside plant whose root and leaves foam like soap-suds in water, used in old herbal medicine for skin complaints and today in natural cleansers. It has not been studied on its own in people.

Traditional use

King's American Dispensatory records soapwort as a 19th-century remedy for skin diseases, syphilis, jaundice and rheumatism, usually given as a decoction, and notes that its root and leaves turn frothy in water like soap-suds. Its extract is now studied as a milder natural alternative to synthetic detergents.

What studies show

No studies in people of this herb on its own yet. What is known of it comes from the traditions that use it.

  • Insufficient

    Skin and acne: no study of soapwort on its own in people was found. A 2020 placebo-controlled trial in 41 young adults with acne used a cream combining soapwort with two other plant extracts, so it cannot show what soapwort alone does. In lab tests a soapwort extract was milder on skin models than common synthetic detergents.

Be careful of

Cautions

  • NoteIts foaming compounds (saponins) irritate the nose, eyes and gut: the 19th-century texts describe the saponin as poisonous and a strong cause of sneezing. Do not inhale the powder, keep it out of the eyes, and do not take it by mouth without a clinician.
  • PregnancyNo safety information for pregnancy or breastfeeding was found in the sources used here. Old texts also attribute to it the power to bring on menstruation, so do not take it by mouth in pregnancy.
  • Ask a clinicianTalk with a clinician or pharmacist before using this if you take prescription medicines, are pregnant or breastfeeding, or are giving it to a child.

From the old books

What herbals and dispensaries of the past printed. History, in their words.

“Soapwort is tonic, diaphoretic, and alterative; and forms a remedy in the treatment of syphilitic, scrofulous and cutaneous diseases, also in jaundice, liver affections, rheumatism, and gonorrhœa.”
Harvey Wickes Felter and John Uri Lloyd, King's American Dispensatory (1905), vol. 2, p. 1724. See the page of King's American Dispensatory, vol. 2, p. 1724 (opens in a new tab) · Read the full passage from King's American Dispensatory, vol. 2, p. 1724

Sources

  1. In vitro and randomized, double-blind, placebo-controlled trial to determine the efficacy and safety of nine antiacne medicinal plants (Evid Based Complement Alternat Med, 2020) — PubMed record (opens in a new tab) · NIH · read September 25, 2026
  2. Soapwort (Saponaria officinalis L.) extract vs. synthetic surfactants — effect on skin-mimetic models (Molecules, 2021) — PubMed record (opens in a new tab) · NIH · read September 25, 2026

Reviewed September 25, 2026.