Herbals and supplements

Pennyroyal Oil A Potentially Toxic Folk Remedy

The Bottom Line

Pennyroyal oil is an herbal extract from a plant in the mint family and has been used for centuries as a folk remedy. Pennyroyal oil is highly toxic, and its use has resulted in severe illness, liver failure, and death.

The Full Story

We don’t hear about pennyroyal oil often. When we do, we have reason to be greatly concerned. Although poisonings with pennyroyal oil are rare, they can be serious and have even led to death.

Pennyroyal oil is extracted from the leaves of the pennyroyal plant, which is in the mint family. Pennyroyal oil has had many folklore medicinal uses for at least 2000 years. Because of its strong spearmint fragrance, it was used as an herb to flavor teas and food and as an insecticide. It is most notable for its use to induce menstruation and abortion. Use of pennyroyal oil has led to severe adverse reactions - and even death.

Herbal medicines are often thought of as "natural," and many people assume that "natural" means "safe." This can be a dangerous belief, as is seen with pennyroyal oil. Young women have died from attempting to induce abortion using pennyroyal oil. Infants have been severely sickened after they were given teas made with pennyroyal thought to be mint.

Pennyroyal oil contains pulegone, which is highly toxic, particularly to the liver. Ingestion can lead initially to gastrointestinal distress such as nausea, vomiting, and abdominal pain. Later on, it can lead to failure of the liver and kidneys, resulting in bleeding, seizures, multiple organ failure, and death.

There is no antidote for pennyroyal oil poisoning. Thus, prevention and early treatment are key.

If you think someone might have swallowed pennyroyal oil, call Poison Control right away at 1-800-222-1222.

Serkalem Mekonnen, RN, BSN, MPH
Certified Specialist in Poison Information

For More Information

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Pennyroyal Oil (Mentha pulgium) [Internet]. Bethesda MD; 2015 Sep 30 [accessed 2016 Feb 29].


Bakerink JA, Gospe SM Jr, Dimand RJ, Eldridge MW. Multiple organ failure after ingestion of pennyroyal oil from herbal tea in two infants. Pediatrics. 1996;98:944-7.

Sullivan JB, Rumack BH, Thomas H, Peterson RB, Bryson P. Pennyroyal oil poisoning and hepatotoxicity. JAMA. 1979;242:2873-4. 


CALL 1-800-222-1222

Prevention Tips

  • Always check with your healthcare provider before taking any traditional medicine, botanical product, tea, herb, or dietary supplement.
  • Never use pennyroyal oil as an insect repellant or as medicine.
  • Never prepare your own herbal medicines.
  • Never give herbs, teas, or dietary supplements to children without consulting their healthcare provider.

This Really Happened

An 18-year-old girl came to an emergency room with abdominal pain, nausea, and vomiting. She was agitated but was also sleepy at times. She was able to tell the physician that she'd swallowed an ounce of pennyroyal oil 2 hours earlier in an attempt to abort a suspected pregnancy. She was admitted to the intensive care unit for monitoring and treatment. She worsened over the next 40 hours. She bled excessively and lost a lot of blood because the pennyroyal oil damaged her liver, which is responsible for the normal clotting abilities of the blood. Her liver was very tender and enlarged, and lab tests showed liver failure. Her kidneys, heart, and lungs also began to fail as a result, so she was placed on a breathing machine. About 6 days after the ingestion, she had cardiac arrest and died.

Sullivan JB, Rumack BH, Thomas H, Peterson RB, Bryson P. Pennyroyal oil poisoning and hepatotoxicity. JAMA. 1979;242:2873-4.