摘要:Background Hypertension is a global health concern for which novel treatment strategies are necessary. The aim of this study is to evaluate the efficacy of resveratrol (trans-3, 5, 4′-trihydroxystilbene, a polyphenol present in grapes) in controlling blood pressure in participants diagnosed with prehypertension and stage 1 hypertension. Methods/design In a randomized, crossover, double-blinded, placebo-controlled study, 50 participants with prehypertension (diastolic blood pressure and systolic blood pressure, 80–89 mmHg and 120–139 mmHg, respectively) and 50 participants with stage 1 hypertension (diastolic and systolic, 90–99 mmHg and 140–159 mmHg, respectively) will be assigned to receive resveratrol (99 % pure, from Biotivia Longevity Bioceuticals LLC Company, USA, in 500 mg capsules, twice daily for 4 weeks, orally) or placebo (500 mg neutral microcellulose capsules, twice daily for 4 weeks) in a 2 × 2 crossover design (4 weeks treatment—4 weeks washout—4 weeks treatment). The blood pressure of each participant will be recorded (a mean of two times within a 15-minute interval) every week during the study. The participants in the prehypertensive group will not receive any medication, while those in the stage 1 hypertensive group will continue to receive their routine medications during the study. Blood samples will be taken from all groups and examined for various biochemical parameters. Discussion This trial will help to establish whether resveratrol is an effective antihypertensive agent in prehypertensive and stage 1-hypertensive patients. The trial outcome will provide novel insight into the clinical efficacy of resveratrol and provide valuable information for conducting future clinical studies with resveratrol. Trial registration Iranian Registry of Clinical Trials, IRCT201407078129N7. Registered on 15 August 2014.