Pennyroyal refers to two plants in the mint family, Lamiaceae. The European pennyroyal, Mentha pulegium, (also called Squaw Mint, Mosquito Plant,^[1] and Pudding Grass^[2]), is a plant in the mint genus, within the family Lamiaceae. Crushed Pennyroyal leaves exhibit a very strong fragrance similar to spearmint. Pennyroyal is a traditional culinary herb, folk remedy, and abortifacient. The essential oil of pennyroyal is used in aromatherapy, and is also high in pulegone, a highly toxic volatile organic compound affecting liver and uterine function.

Culinary and medicinal uses

Pennyroyal was commonly used as a cooking herb by the Greeks and Romans. The ancient Greeks often flavored their wine with pennyroyal. A large number of the recipes in the Roman cookbook of Apicius call for the use of pennyroyal, often along with such herbs as lovage, oregano and coriander. Althoughout was commonly used for cooking in the Middle Ages, it gradually fell out of use as a culinary herb and is seldom used so today.

Even though pennyroyal oil is extremely poisonous, people have relied on the fresh and dried herb for centuries. Early settlers in colonial Virginia used dried pennyroyal to eradicate pests. Pennyroyal was such a popular herb that the Royal Society published an article on its use against rattlesnakes in the first volume of its Philosophical Transactions in 1665.^[3]

Pennyroyal tea is the use of an infusion made from the herb. The infusion is widely reputed as safe to ingest in restricted quantities. It has been traditionally employed and reportedly successful as an emmenagogue (menstrual flow stimulant) or as an abortifacient. Pennyroyal is also used to settle an upset stomach^[4] and to relieve flatulence.^[5] The fresh or dried leaves of pennyroyal have also been used when treating colds, influenza, abdominal cramps, and to induce sweating,^[4] as well as in the treatment of diseases such as smallpox and tuberculosis, and in promoting latent menstruation.^[5] Pennyroyal leaves, both fresh and dried, are especially noted for repelling insects.^[4] However, when treating infestations such as fleas, using the plant's essential oil should be avoided due to its toxicity to both humans and animals, even at extremely low levels.^[6]

Pennyroyal essential oil also works as a bug repellent to keep away ticks, mosquitoes and other biting and stinging pests. Planting pennyroyal around your house can discourage bugs from taking up residence in the yard, and keeping a vase of fresh pennyroyal in a room can not only drive potential pests away but kill the ones already occupying the area. Again, pennyroyal is toxic and should only be used in small amounts and for external use only. Pregnant women should avoid exposure altogether.

Toxicity

Pennyroyal

Pennyroyal essential oil is extremely concentrated. It should never be taken internally because it is highly toxic; even in small doses, consumption of the oil can result in death.^[7] The metabolite menthofuran is thought to be the major toxic agent. Complications have been reported from attempts to use the oil for self-induced abortion. For example, in 1978 an eighteen year-old pregnant woman from Denver, Colorado died within one week after consuming one ounce of concentrated Pennyroyal oil in an attempt to self-induce abortion.^[8] There are numerous studies that show the toxicity of pennyroyal oil to both humans and animals.^{[9][10][11][12]}

Since the U.S. Congress passed the Dietary Supplement Health and Education Act in October 1994, all manufactured forms of pennyroyal in the United States have carried a warning label against its use by pregnant women. This substance is not regulated by the U.S. Food and Drug Administration.^[13]

Attributed and possible contributions to death

• 1897- A twenty-three year old British woman died eight days after swallowing a tablespoon of pennyroyal in order to induce menstruation.^[7]
• circa 1909- The Supreme Court of Indiana convicted a Mr. Carter of prescribing and administering pennyroyal pills to a pregnant woman who died two months after her miscarriage.^[14]
• August 1912- A sixteen year-old girl from Maryland consumed thirty-six pennyroyal pills to induce abortion.^[7] An autopsy revealed that the herbal abortion was only partially successful, and was later, "...completed by mechanical means..." before the girl's death.^[7]
• November 1978- An eighteen year-old pregnant woman from Denver, Colorado died after ingesting one ounce of concentrated pennyroyal oil in an effort to abort her fetus.^[8] Prior to her death, the victim had reported using the dried leaves of the plant to induce menstruation with no ill effects.^[8]
• July 1994- Kris Humphrey, a twenty-four year-old woman, died in California.^[15] At the time of her death, Humphrey unknowingly had an ectopic pregnancy, and drank a tea made with pennyroyal extract.^[15] According to one news report, there is disagreement over whether Humphrey died as a result of the ectopic pregnancy or from pennyroyal poisoning.^[15]

Historical and literary mentions

plant

In Maine writer, Sarah Orne Jewett's novel, Country of the Pointed Firs, one of the residents of Dunnet, Maine whom the narrator befriends, Mrs. Todd, harvests pennyroyal in a field north of the town.

In the Homeric Hymn of Demeter, Demeter in the guise of an old woman as she searches for the abducted Persephone refuses red wine but accepts a drink of barley, water and pennyroyal called kykeon.

Aristophanes made reference to pennyroyal as abortifacient in Lysistrata and Peace. Mari Sandoz writes in her book, Slogum House, "She was the fifth of twelve children in the river-bottom family, with a mother who laid the cards and brewed tansy, pennyroyal and like concoctions for luckless girls who were in need."

George Washington Sears includes his recipe for an insect repellent which contains pennyroyal oil in a number of his writings.

The grunge band Nirvana recorded a song named "Pennyroyal Tea."

In the book Jitterbug Perfume by Tom Robbins, pennyroyal is used by Kudra to keep from becoming pregnant.

William Carlos Williams opens his "Kora in Hell: improvisations" city lights books with "Fools have big wombs. For the rest? - here is pennyroyal if one knows to use it. But time is only another liar so go along the wall a little further......"

In the Mortal Engines by Philip Reeve, Professor Pennyroyal is a bogus historian who leads the protagonists of the story to near death.

In the Science Fiction book "The Technician" by Neal Asher, Penny Royal is the name of rogue black AI.

The musician Jesca Hoop mentions "Pennyroyal wine" in her 2008 song, Enemy.

See also

• Hedeoma pulegioides (American Pennyroyal, a distantly related species)

References