
Background: Hypertension is a leading risk factor for cardiovascular disease, particularly in ageing populations. While pharmacological interventions are common, issues with long-term adherence and side effects have prompted interest in alternative treatments. Cannabidiol (CBD), a non-psychoactive component of Cannabis sativa, has been proposed as a potential agent for blood pressure regulation due to its anxiolytic, anti-inflammatory, and vasodilatory properties. This systematic review aimed to evaluate the effects of oral CBD supplementation on blood pressure in adults with normotension and hypertension.
Methods: A systematic search of PubMed, Web of Science, Scopus, and Medline was conducted in September 2024. Eligible studies were randomised controlled trials (RCTs) involving oral CBD administration in normotensive or hypertensive adults, with blood pressure as an outcome. Studies involving animals, inhaled CBD, or non-English texts were excluded. Risk of bias was assessed using the Cochrane Risk of Bias tool. Clinical heterogeneity was assessed by comparing study populations, CBD dosing regimens, outcome measures, and assessment conditions. Substantial variability in dosing and blood pressure outcome reporting precluded quantitative pooling; therefore, results were synthesised narratively due to clinical heterogeneity.
Results: Four RCTs involving 120 participants met the inclusion criteria. Studies varied in CBD dose (225-600 mg/day), duration (two hours to 5 weeks), and participant health status. An association was observed between CBD dosage (mg/day) and reductions in blood pressure indicators, with greater reductions occurring at higher doses. All four studies reported statistically significant reductions in systolic blood pressure compared to placebo, particularly under stress or during sleep. Two studies reported lower diastolic pressure. The strongest effects were observed with acute administration of the highest-dose studies of 600 mg/day. Side effect severity was generally mild to moderate, including nausea, diarrhoea, and fatigue. No serious cardiovascular events were reported.
Conclusion: Oral CBD may reduce blood pressure amongst healthy and hypertensive individuals, particularly under stressful conditions and during sleep. Limitations included small sample sizes, short trial durations, variability in CBD matrices and dosages, lack of pharmacokinetic data, and uncertainty surrounding hepatic safety. Larger, longer-term trials with homogeneous supplementation strategies and bioavailability measures are needed to determine CBD’s therapeutic role in blood pressure management.”
https://pubmed.ncbi.nlm.nih.gov/42321899
https://link.springer.com/article/10.1186/s42238-026-00463-3








