Clinical Research Directory

Inclusion Criteria: Aged 18-65 years. Meet two of the five metabolic syndrome criteria. Not taking prescribed medication specifically intended to manage blood pressure, blood glucose or blood lipids. Able to complete written questionnaires independently. Able to provide informed consent. Exclusion Criteria: Diagnosed diabetes mellitus. Known cardiovascular disease or clinically significant cardiovascular comorbidity, including coronary heart disease, symptomatic heart failure, clinically significant arrhythmia, or a history of stroke or transient ischaemic attack within the previous six months. Known or suspected secondary hypertension, including renal, renovascular or endocrine causes. Known clinically significant renal impairment or severe hepatic disease. Evidence or history of hypertension-related target-organ damage requiring specialist management. Pregnant or lactating. Allergy or known intolerance to peppermint or any ingredient contained in the intervention or placebo. Habitual consumption of peppermint products. Regular consumption of antioxidant or other dietary supplements likely to influence cardiometabolic outcomes. Body mass index greater than 40.0 kg/m². Current enrolment in another clinical trial or use of another intervention or therapy likely to influence the study outcomes. Any condition likely to compromise informed consent, protocol compliance or outcome assessment, including severe psychiatric illness, cognitive impairment, or active substance or alcohol misuse.