Oral CBD May Help Lower Blood Pressure, New Review Finds

A new systematic review published by the Journal of Cannabis Research found that oral cannabidiol (CBD) may help reduce blood pressure in adults, particularly during periods of stress and while sleeping.

The review, conducted by researchers at University College London, examined randomized controlled trials evaluating oral CBD supplementation in adults with either normal blood pressure or hypertension. Researchers searched PubMed, Web of Science, Scopus and Medline, ultimately identifying four trials involving 120 participants.

Across the studies, CBD doses ranged from 225 mg to 600 mg per day, with study durations ranging from two hours to five weeks. Due to differences in dosing, study design and how blood pressure outcomes were measured, researchers did not conduct a pooled meta-analysis and instead summarized the findings narratively.

All four studies included in the review reported statistically significant reductions in systolic blood pressure compared to placebo. The strongest effects were observed in studies using higher doses, particularly acute administration of 600 mg. Two studies also found reductions in diastolic blood pressure.

The review found that CBD’s blood-pressure-lowering effects appeared most notable under stressful conditions and during sleep. Researchers said this may be related to CBD’s potential anxiolytic, anti-inflammatory and vasodilatory effects, though they emphasized that the evidence remains limited.

Side effects reported in the reviewed trials were generally mild to moderate, including nausea, diarrhea and fatigue. No serious cardiovascular events were reported.

“Oral CBD may reduce blood pressure amongst healthy and hypertensive individuals, particularly under stressful conditions and during sleep,” the researchers concluded.

However, the authors noted several limitations, including the small number of studies, limited sample sizes, short trial durations, variation in CBD formulations and doses, and uncertainty around long-term liver safety. They said larger and longer trials are needed before CBD’s potential role in blood pressure management can be determined.