Historical essay
Pennyroyal, Mifepristone, and the Long History of Medication Abortions

Pennyroyal, Mifepristone, and the Long History of Medication Abortions

Kathleen Crowther

Around midnight on September 16, 1866, Dr. W. A. Wilcox of Saint Louis, Missouri, was called to the home of “Mrs. L,” a thirty-year-old married mother of two. Mr. L had been out for the evening and returned home at eleven to find his wife unconscious. When Dr. Wilcox arrived, Mrs. L was pale and clammy; her breathing was heavy, her pulse was “feeble and quick,” and her extremities were cold. Her pupils did not contract when he shone light directly at them. Believing that she might have overdosed on opium, he forced “an emetic and fifteen to twenty drops of fluid extract of belladonna” down her throat every half hour and waited. After about three hours, Mrs. L began vomiting and regained consciousness. “The vomited matter,” Wilcox observed, “consisted of liquid smelling strongly of pennyroyal.”[1] When Mrs. L recovered enough to talk to the doctor, she told him she “had taken a teaspoonful of oil of pennyroyal” at nine in the evening before she went to bed. She had done this “in order to bring on her menses, which had been due several days.” Dr. Wilcox made no comment on this, except to note that Mrs. L began menstruating on September 17.

While “bringing on the menses” may sound to modern readers like code for abortion, it is impossible to say for certain that Mrs. L was trying to terminate a pregnancy. Regular menstruation was considered essential for a woman’s health, and many women took drugs – called “emmenagogues” – to bring on their menses if they were late. Most of the drugs used as emmenagogues could also be used as abortifacients. In Missouri in 1866, “bringing on the menses” was perfectly legal; inducing an abortion was not. Mrs. L may have lied to Dr. Wilcox about her intentions – or she may have been perfectly straightforward.

The drug in question, pennyroyal, is a species of mint with purple flowers. It smells like spearmint. And it has been used as an abortifacient for over two thousand years.

About half of all abortions in the United States are now medication abortions. In the past, that percentage was much higher. Up until the 20th century, most abortions, like Mrs. L’s, were medication abortions. A “surgical” abortion involved penetrating the cervix with some kind of sharp instrument. It was agonizingly painful and extremely dangerous. Even if the operation was successful at terminating the pregnancy, the ensuing infection could be deadly. Only with the advent of anesthesia and antisepsis in the late nineteenth century did surgical abortions become anything other than a desperate last resort. Most abortions were managed with medication, administered orally, vaginally, or topically. The medicines used were almost all herbal, and most had very long histories.

A clear glass bottle with yellowish liquid inside.
A glass bottle used to hold liquid preparations, c. 1850. The label “TR:PULEGII” is the abbreviated Latin for pennyroyal water, which was made from a strained infusion of leaves. (Courtesy Wellcome Collection)

Pennyroyal, which Mrs. L. ingested, has been used since antiquity to induce abortions. We can find ample evidence of the use of abortifacient drugs in the medical literature of ancient Greece and Rome. In his encyclopedic On Medical Material (usually known by its Latin title, De materia medica), the Greek physician Dioscorides (ca. 40–90 C.E.) described multiple methods and substances used to induce an abortion. According to Dioscorides, you could end a pregnancy by giving a woman rue or pennyroyal to drink, by rubbing the juice of cyclamen on her hips and navel, by boiling tansy and placing it in her bath, or by pounding the leaves of catnip into a pessary to be inserted into the vagina.[2]

In his Natural History, the Roman writer Pliny the Elder (23/24 –79 C.E.) noted the abortifacient properties of several herbs, including wild mustard plant and squirting cucumber.[3] As the name “squirting cucumber” suggests, many plants used as abortifacients, or for other aspects of reproductive medicine like contraception or fertility aids, had obvious phallic connotations.[4] In his Gynecology, the Roman physician Soranus (active ca. 1st/2nd century C.E.) provides recipes for compounds to be taken orally or to be administered as vaginal suppositories to induce abortions. The substances in these include rue, myrtle, myrrh, white pepper, rocket, cow parsnip, cardamom, and bay leaves.[5]

Many of the abortifacient herbs and plants described by Greek and Roman writers continued to show up in medical texts for the next two thousand years. “Pennyroyal boiled in wine and drunken, provoketh the monthly terms, bringeth forth the secondine [placenta], the dead child and unnatural birth,” wrote the English herbalist John Gerard (1545-1612). Historian John Riddle has pointed out that many of the plants used by the ancients to induce abortions really do contain chemicals capable of terminating pregnancies. These plants include pennyroyal, rue, tansy, catnip, sage, myrtle, myrrh, and squirting cucumber. Pennyroyal and catnip, for example, both contain the organic compound pulegone, which is an abortifacient.[6] Many pre-modern abortion drugs would produce the desired effect if taken in the correct amount – though this was a big “if.” The amount of pharmacologically active chemicals in plants varies according to season, soil, and other conditions. And most of these plants, like pennyroyal, can be lethal in large doses.

For the past two decades, medication abortions in the United States have been carried out with a combination of two drugs: mifepristone and misoprostol. Mifepristone blocks progesterone, a hormone necessary to maintain a pregnancy. Misoprostol stimulates contractions to expel the contents of the uterus. Together they are 99.6% effective at ending pregnancy within the first ten weeks, and they are safer than other commonly used drugs such as ibuprofen, penicillin, and Viagra. We have come a long way from the days when women like Mrs. L risked death when they swallowed abortifacient drugs.

And yet, the legal status of mifepristone hangs in the balance. Matthew Kacsmaryk, a federal judge in Texas, presided over Alliance for Hippocratic Medicine v. U.S. Food and Drug Administration, a case brought by anti-abortion advocates seeking to reverse the FDA’s approval of mifepristone. On April 7, 2023, Kacsmaryk, a conservative Trump appointee, ruled for the plaintiffs, a decision that could jeopardize access to mifepristone throughout the United States. In response, abortion providers have come up with protocols for medication abortions using just misoprostol. But when misoprostol is used on its own, the side effects (nausea, vomiting, diarrhea) are worse, and the efficacy is reduced (from 99.6% to 93%). Of course, misoprostol is still considerably safer and more effective than pennyroyal, rue, or tansy. But chipping away at access to safe medication abortions is deeply disturbing. Mrs. L’s case in 1866 is a poignant reminder that banning abortifacient drugs does not stop people from seeking them out. It just makes medication abortions less safe. Mrs. L ingested oil of pennyroyal, the most concentrated form of pennyroyal and therefore the most dangerous. In the late nineteenth century, pennyroyal preparations were easily obtainable at pharmacies and by mail order, and widely advertised as effective for all manner of “female complaints,” but there were no regulations in this period that would have ensured quality or standardized concentration. Perhaps if Mrs. L had been able to consult a physician or midwife openly, she might have been advised to try a milder form of the drug, with less devastating consequences.

A blister pack of white pills with "Mifepristone" written in red lettering on the back.
A package of mifepristone pills. (Courtesy Wikimedia)

Mrs. L’s experience is especially relevant in the post-Roe reproductive landscape. Since May 2022, when a draft of the Dobbs v. Jackson Women’s Health Organization decision was leaked to the press and it became apparent that the U.S. Supreme Court was about to overturn Roe v. Wade, there has been a surge of interest in the herbal abortifacients of the past. In June 2022, Rolling Stone magazine reported a dramatic increase in TikTok videos promoting herbal abortifacients. The article also noted that Google searches for pennyroyal, blue cohosh, and mugwort had “skyrocketed.” When I looked up the e-book version of What to Expect When You’re Expecting on the Amazon website, I could view “popular highlights,” which are passages that Kindle readers have highlighted. Over 1,400 Kindle readers have highlighted the following passage: “Pregnant women should particularly avoid the following oils, because some of them can trigger uterine contractions: basil, juniper, rosemary, sage, peppermint, pennyroyal, oregano, and thyme.” Maybe some readers want to remind themselves that these essential oils are dangerous during pregnancy. But in the current political climate, where seeking information about abortions could trigger a police investigation, I find the intense interest in abortifacient herbs to be very worrying.

Many physicians have pointed to the high toxicity of these substances and the very limited data on their efficacy. Pennyroyal, for example, can cause severe liver damage and death. Mrs. L’s close call was no fluke; most people who ingest pennyroyal in a quantity sufficient to induce an abortion will end up vomiting and enduring abdominal pain, if they do not slip into a coma and die. Mrs. L was lucky to survive, and her ordeal should make clear that herbal remedies are not necessarily “gentle” or “natural.” The herbs used to induce abortion in the past were—and are—dangerous. Too high a dose and they were toxic; too low and they were ineffective.

The coat hanger has long been a symbol of the dangerous back-alley abortions that killed women in the decades before Roe v. Wade. Now that medication abortions are under threat, we should remember that pennyroyal and other herbs could be deadly, too.


  1. W. A. Wilcox, “Poisoning by Pennyroyal.” Boston Medical and Surgical Journal 78 (1868): 394. This case is cited in Kaye Wierzbicki, “A Cup of Pennyroyal Tea.” The Toast, May 27, 2015. https://the-toast.net/2015/05/27/a-cup-of-pennyroyal-tea/” I discuss the case at greater length in my forthcoming Policing Pregnant Bodies From Ancient Greece to Post-Roe America (Baltimore. Johns Hopkins University Press, 2023).
  2. Dioscorides, De materia medica, trans. T. A. Osbaldeston and R. P. A. Wood (Johannesburg, South Africa: Ibidis Press, 2000), rue p. 423, pennyroyal p. 404, cyclamen p. 324, tansy p. 513, catnip p. 412.
  3. Pliny, Natural History, vol. 6, bk 20, wild mustard, p. 145 and squirting cucumber, p. 9.
  4. Laurence M.V. Totelin, “Sex and vegetables in the Hippocratic gynaecological treatises” Studies in the History and Philosophy of Biology and Biomedical Sciences 38 (2007): 531-540.
  5. Soranus’ Gynecology. Translated with introduction by Owsei Temkin. (Baltimore: Johns Hopkins University Press, 1956), pp. 62-68.
  6. John M. Riddle, Eve’s Herbs: A History of Contraception and Abortion in the West (Cambridge, MA: Harvard University Press, 1997), pp. 40-63.

Featured image caption: Pennyroyal (Mentha pulegium) and creeping thyme (Thymus serpyllum): entire flowering plants. Coloured etching by C. Pierre, c. 1865, after P. Naudin. (Courtesy Wellcome Collection)

Kathleen Crowther is an associate professor in the Department of the History of Science at the University of Oklahoma. Her research interests include science, medicine, gender and religion in the early modern period. Her first book was Adam and Eve in the Protestant Reformation (Cambridge University Press, 2010). One of her current projects is an examination of anatomical studies of reproduction, including the anatomy of the male and female reproductive organs and of fetal development, in the sixteenth and seventeenth centuries.

3 thoughts on “Pennyroyal, Mifepristone, and the Long History of Medication Abortions

    • Author gravatar

      Very useful, informative and important article. Women with unwanted pregnancies often become desperate and will seek any means possible to terminate jay pregnancy. Thank you for posting this.

    • Author gravatar

      To clarify, US providers did not develop misoprostol-only protocols in response to the Texas decision. They have been widely shared and available by the World Health Organization at least since 2012, because misoprostol is available and inexpensive globally, where mifepristone is not. It’s important to avoid American exceptionalism, just as it’s important to avoid abortion exceptionalism.

      I’m also troubled as a provider by the lack of clear distinctions drawn here between oil of pennyroyal and pennyroyal tea, for example. Oil of pennyroyal — referenced in the report of Mrs. L — is extremely toxic in small doses, and can be fatal. Herbal abortifacients do have a long history, but the nuances of their use are important, and often lost when their use was criminalized. There are ethical concerns given the current legal landscape to not emphasizing those nuances or the lack of knowledge around dosage, efficacy, preparation, and safety.

    • Author gravatar

      Excellent essay. Thank you.

Comments are closed.