Side Effects of Peppermint Oil
In most adults, the small doses of peppermint oil contained in dietary supplements and skin preparations appear to be safe. Pregnant and breastfeeding women, however, should avoid such products because little is known about their safety during pregnancy and lactation.
Possible side effects of peppermint oil include:
- Allergic reactions such as flushing, headache, and mouth sores
- Anal burning during bouts of diarrhea
Although enteric-coated peppermint oil capsules may reduce the risk of heartburn, their protective coating can break down more quickly and increase the risk of heartburn when taken at the same time as prescription and over-the-counter medications that decrease stomach acid and which are often used for heartburn or acid reflux. It's best to take such drugs at least two hours after taking enteric-coated peppermint oil products. A stomach condition called achlorhydria, in which the stomach doesn't produce hydrochloric acid, also may hasten the coating's breakdown. So people with the condition are advised against using peppermint oil.
Possible Drug Interactions With Peppermint Oil
Before taking peppermint oil, discuss the risks and benefits with your health care provider. Some supplements can interact with medicine. Interactions can be harmful or make medications not work as they should.
Be cautious about combining peppermint oil with certain drugs because it may inhibit the body's ability to metabolize the drugs and increase the risk of side effects. According to the Natural Medicines Comprehensive Database, there is a moderate risk in combining peppermint oil with the immunosuppressant drug cyclosporine (Neoral, Sandimmune) and many different medications that are changed and broken down by the liver.