A small daily dose of peppermint oil may help lower blood pressure in people with mildly elevated readings, according to new research from the University of Lancashire published in the journal PLOS One.
The study found that participants who took 100 microliters of peppermint oil twice a day for 20 days saw their systolic blood pressure—the top number in a blood pressure reading—fall by an average of 8.5mmHg. Those given a peppermint-flavoured placebo without the active oil showed no meaningful change over the same period.
Researchers enrolled 40 adults aged between 18 and 65, all of whom had prehypertension or stage 1 hypertension, and randomly split them into two groups. One group received the peppermint oil, while the other received the placebo, allowing researchers to compare outcomes between the two.
Alongside the primary measure of systolic blood pressure, the research team also tracked a range of secondary outcomes, including diastolic blood pressure, heart rate, body measurements, blood test results, mental well-being and sleep quality.
Peppermint naturally contains compounds such as menthol and flavonoids, which the researchers investigated as possible contributors to the observed effect on blood pressure.
Lead author Dr Jonnie Sinclair, Reader in Sport and Health Sciences at the University of Lancashire, said high blood pressure remains one of the leading causes of heart disease and death worldwide, as well as a significant financial burden on healthcare systems.
"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," Dr Sinclair said.
He described the findings as having "significant clinical implications," particularly given that arterial hypertension is considered the most common preventable risk factor for cardiometabolic disease and the single greatest risk factor for mortality globally.
"Our findings were very positive," Dr Sinclair added. "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."
The researchers noted that peppermint oil could represent a low-cost, well-tolerated alternative or complement to existing treatments for people with slightly elevated blood pressure, though further research would likely be needed to confirm the findings across larger and more diverse populations.
High blood pressure, or hypertension, is a widespread condition that often develops without obvious symptoms but significantly raises the risk of heart attack, stroke and other cardiovascular complications over time. Current treatment typically involves lifestyle changes such as diet and exercise, alongside medication where necessary, but access to affordable and effective long-term options remains a challenge in many parts of the world.
The study's authors said the affordability and simplicity of peppermint oil could make it a particularly attractive option for large-scale public health approaches, especially in settings where access to conventional medicines is limited or costly.
The research was conducted by a team at the University of Lancashire and materials describing the findings were provided by the university. The full study has been published in PLOS One, a peer-reviewed scientific journal.
