Researchers at the University of Lancashire found that taking 100 microliters of peppermint oil twice a day for 20 days reduced systolic blood pressure (the top number in a blood pressure reading) by an average of 8.5mmHg.

The findings, published in PLOS One, suggest peppermint oil could provide a simple, inexpensive, and well-tolerated option for people with slightly elevated blood pressure.

A Potential Low-Cost Approach to Blood Pressure

Lead author Dr. Jonnie Sinclair, Reader in Sport and Health Sciences, said: "High blood pressure is one of the biggest causes of heart disease and death worldwide, and it costs a huge amount of money to treat. Although medicines are commonly used to treat it, it's not always clear how well they work in the long-term, and they can cause unwanted side effects."

Peppermint naturally contains compounds including menthol and flavonoids. To investigate its possible effects, researchers enrolled 40 adults between the ages of 18 and 65 and randomly assigned them to two groups.

Participants with prehypertension or stage 1 hypertension in one group received a small daily amount of peppermint oil. The comparison group received a peppermint-flavored placebo without the active oil. Blood pressure improved in the peppermint oil group, while the placebo group showed no meaningful change.

Researchers Tracked More Than Blood Pressure

Although systolic blood pressure was the main focus, the researchers also examined several other measures. These included body measurements, blood test results, diastolic blood pressure (the bottom number in a blood pressure reading), heart rate, mental well-being and sleep quality.

Dr. Sinclair added: "Our findings were very positive and they have significant clinical implications, especially given arterial hypertension is the most common preventable risk factor for cardiometabolic disease and the greatest single risk factor for global mortality.

"Peppermint oil is low in calories and price so it's proved to be a very simple and cost-effective solution to potentially treat millions of people around the world."