Peppermint Oil Lowers Blood Pressure in Just 20 Days, Trial Finds

Daily peppermint oil may offer a simple way to reduce mildly elevated blood pressure, according to a new randomized trial. 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 8.5 mmHg. The findings were published in the journal PLOS One.

The trial enrolled 40 adults between 18 and 65 with prehypertension or stage 1 hypertension, randomly assigning them to two groups. One group received a small daily dose of peppermint oil, while 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.

Peppermint naturally contains compounds including menthol and flavonoids. Besides systolic blood pressure, the researchers also tracked diastolic blood pressure (the bottom number in a reading), body measurements, blood test results, heart rate, mental well-being and sleep quality.

"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," said lead author Dr. Jonnie Sinclair, Reader in Sport and Health Sciences at the University of Lancashire.

Sinclair said the findings have significant clinical implications, since arterial hypertension is the most common preventable risk factor for cardiometabolic disease and the single greatest risk factor for death worldwide.