What is it?
Despite serious safety concerns, pennyroyal is used for the common cold, pneumonia, fatigue, ending a pregnancy (abortion), and as an insect repellant, but there is no good scientific evidence to support these uses.
In manufacturing, pennyroyal oil is used as a dog and cat flea repellent, and as a fragrance for detergents, perfumes, and soaps.
How effective is it?
Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, Ineffective, and Insufficient Evidence to Rate.
The effectiveness ratings for PENNYROYAL are as follows:
Insufficient evidence to rate effectiveness for...
- Ending a pregnancy (abortion).
- Canker sores.
- Common cold.
- Indigestion (dyspepsia).
- Gas (flatulence).
- Gallbladder disease.
- Insect repellant.
- Liver disease.
- Mosquito repellant.
- Stomach pain.
- Other conditions.
Is it safe?
When applied to the skin: Pennyroyal oil is LIKELY UNSAFE when applied to the skin.
Special precautions & warnings:Pennyroyal is LIKELY UNSAFE for anyone to use, but it is especially unsafe for people with the following conditions.
Pregnancy and breast-feeding: It is LIKELY UNSAFE to take pennyroyal by mouth or apply it to your skin when pregnant or breast-feeding. There is some evidence that pennyroyal oil can cause abortions by causing the uterus to contract. But the dose needed in order to cause an abortion could kill the mother or cause life-long kidney and liver damage.
Children: It is LIKELY UNSAFE to give children pennyroyal by mouth. Infants have developed serious liver and nervous system injuries, or even death, after taking pennyroyal.
Kidney disease: The oil in pennyroyal can damage the kidney and make existing kidney disease worse.
Liver disease: The oil in pennyroyal can cause liver damage and might make existing liver disease worse.
Are there interactions with medications?
- Acetaminophen (Tylenol, others)
- Pennyroyal can cause liver damage. Taking pennyroyal with acetaminophen, which can also cause liver damage, might increase the risk for liver damage.
Are there interactions with herbs and supplements?
- Pennyroyal might reduce the absorption of iron from supplements.
Are there interactions with foods?
- Iron-containing foods
- Pennyroyal might reduce the absorption of iron from foods.
How is it typically used?
To learn more about how this article was written, please see the Natural Medicines Comprehensive Database methodology.
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