Pennyroyal (Mentha pulegium)
Photo: Katya from Moscow, Russia · CC BY-SA 2.0
- Licensed photo
Overview
Pennyroyal (Mentha pulegium) is a strongly aromatic perennial mint growing up to about 16 in (40 cm), with oval, serrated leaves and whorls of small, lilac flowers. Often used as an herbal tea to encourage sweating, pennyroyal helps break fevers, soothe colds, and promote digestion. Historically prized for menstrual regulation and as a flea repellent.
Traditional uses & properties
Antispasmodic & Carminative: Helps relieve colic, gas, flatulence, and mild digestive cramps. Diaphoretic: Encourages sweating, aiding in fever management and symptom relief for colds. Emmenagogue: Can help stimulate or regulate menstruation (avoid if pregnant or if bleeding is heavy). Insect Repellent: Known to repel fleas and mosquitoes; used in sachets or as a dilute external spray.
Traditional preparations
Preparation amounts are not shown for this herb. It is toxic, restricted, or otherwise unsafe to self-dose - the margin between a traditional dose and a harmful one is too small to publish as reference material. If you are considering it, that conversation belongs with a doctor or a qualified practitioner, not a website.
Safety & precautions
Pregnancy: Stimulates uterine contractions; avoid during pregnancy. Essential Oil: Highly toxic if ingested (reports of fatalities); do not take internally. Menstrual Flow: Avoid if you already have heavy bleeding.
Drug & food interactions
Pennyroyal may reduce the absorption of iron compounds.
- Herbal medicines
- No interactions found.
- Food
- No interactions found.
- Iron compounds
- Pennyroyal tea reduces iron absorption similarly to conventional tea. In a study in 9 healthy subjects, a 275mL serving of pennyroyal tea reduced the absorption of iron in a 50 g bread roll by about 70%. The tea was prepared by adding 300mL of boiling water to 3 g of the herbal tea, then infusing for 10 minutes before straining and serving. In this study, the inhibitory effect of pennyroyal tea on iron absorption was modestly less than that of black tea (Assam tea, Camellia sinensis L.), which is known to inhibit iron absorption.
These entries keep the wording of the reference they come from, and three phrases mean three different things. "No interactions found" means the source looked for reports of that pairing and found none. "No data found" means nothing has been published either way. "Based on experimental evidence only" means the effect has been seen in a laboratory or animal study but not in people - a reason for caution, not a report of harm.
Habitat
Native to Europe and western Asia, and now naturalized in the Americas, pennyroyal grows in damp places and is gathered when flowering in summer. The aerial parts (leaves and flowers) are dried or used fresh.
Frequently asked questions
What is Pennyroyal (Mentha pulegium) traditionally used for?
Traditional sources describe Pennyroyal (Mentha pulegium) as follows: Antispasmodic & Carminative: Helps relieve colic, gas, flatulence, and mild digestive cramps. Diaphoretic: Encourages sweating, aiding in fever management and symptom relief for colds. Emmenagogue: Can help stimulate or regulate menstruation (avoid if pregnant or if bleeding is heavy). Insect Repellent: Known to repel fleas and mosquitoes; used in sachets or as a dilute external spray.
How is Pennyroyal (Mentha pulegium) prepared?
Preparation amounts are not shown for this herb. It is toxic, restricted, or otherwise unsafe to self-dose - the margin between a traditional dose and a harmful one is too small to publish as reference material. If you are considering it, that conversation belongs with a doctor or a qualified practitioner, not a website.
What safety cautions apply to Pennyroyal (Mentha pulegium)?
Pregnancy: Stimulates uterine contractions; avoid during pregnancy. Essential Oil: Highly toxic if ingested (reports of fatalities); do not take internally. Menstrual Flow: Avoid if you already have heavy bleeding.