Last updated 9 August 2026 · Originally published 9 May 2020
High blood pressure affects roughly a third of adults worldwide, and it’s the sort of condition where “natural alternative” marketing finds a ready audience. So it’s worth being clear about two things up front.
CBD has produced a genuine blood-pressure-lowering signal, including in one randomised trial involving people with hypertension. That makes it one of the more promising cardiovascular findings — not an established treatment. And it is nowhere near being a substitute for hypertension medication, which prevents strokes and heart attacks in a way nothing here has been shown to do.
What the trials found
The early work was in healthy volunteers. A 2017 study gave nine men a single 600 mg dose and found reduced blood pressure alongside a modest rise in heart rate.[1] A follow-up in 26 healthy men, dosing over seven days, found the acute drop in mean arterial pressure tapered with continued use — though blood pressure under stress stayed lower, and there were signs of improved arterial function.[2]
Interesting, but healthy men in their twenties aren’t the people asking this question.
The hypertension trial
That changed with HYPER-H21-4, a randomised, placebo-controlled crossover trial in Croatia — the first proper test of repeated CBD dosing in people who actually have high blood pressure.
Seventy patients with mild or moderate primary hypertension were randomised. Some were untreated; others continued their usual blood-pressure medication. Sixty-six completed both periods, and usable 24-hour blood-pressure data were available for 61. Doses were substantial: 225–300 mg daily for the first half, rising to 375–450 mg, split into three doses.
During the CBD period, average 24-hour systolic pressure fell by about 4.8 mmHg, diastolic by 2.3 mmHg and mean arterial pressure by 3.2 mmHg after two and a half weeks. Nothing significant happened during the placebo period.[3] The reductions held at five weeks — though notably, increasing the dose halfway through produced no additional drop.
Sub-analyses found reductions in catestatin and urotensin-II, signalling molecules involved in blood-pressure regulation, which offer possible clues to how the effect occurs.[4,5] But these were substudies of the same trial, and changes in biomarkers don’t establish a mechanism.
Two caveats that matter. The trial used DehydraTECH, a proprietary delivery formulation designed to improve absorption, and it was funded by the company that makes it. And seventy patients over five weeks is a small, early trial — not a basis for changing treatment.
What about heart rate?
Less clear, and the findings don’t all point the same way.
The 2017 single-dose study found heart rate increased slightly. Other work suggests CBD may have a modest influence on how the nervous system regulates the heart, and a 2021 study of five oral preparations concluded the effect on heart rate variability was modest at best.[6]
Worth separating CBD from THC here, because they behave differently. THC raises heart rate more consistently and has been associated with arrhythmias in susceptible people. CBD’s cardiovascular effects appear smaller and less consistent — but it isn’t completely inert, as that 2017 finding shows.
The part that matters most
If you take blood pressure medication, this is a conversation to have with your doctor before adding CBD.
CBD may interact with cardiovascular drugs. It affects enzymes involved in processing some calcium channel blockers, beta blockers and statins, though direct clinical evidence for many specific combinations is limited. CBD may also add to the blood-pressure-lowering effect of medication you’re already taking.
The hypertension trial did include 32 people on standard treatment, and reported no observed drug interactions over its five weeks. Reassuring — but not enough to establish that every combination is safe. Ask your doctor or pharmacist.
Don’t stop or reduce prescribed medication. Hypertension is largely symptomless, which is exactly what makes it dangerous. You won’t feel it getting worse. The medication is preventing strokes and heart attacks, and no CBD trial has tested anything like that.
Tell whoever monitors your blood pressure. If CBD is lowering it, that’s information they need when adjusting your doses.
Where this leaves it
Blood pressure is one of the more promising areas of CBD research, and unusually it’s an area where a proper trial in patients exists rather than only healthy volunteers.
But that trial was small, short, used a specialised formulation at doses far above a typical retail product, and was funded by the formulation’s manufacturer. Independent replication at scale would change the picture; nothing yet has.
So: promising enough to follow, not established enough to act on alone. If you have hypertension and want to try CBD, do it with your doctor’s knowledge and without stopping or reducing your prescribed treatment.
None of this is medical advice.
For more, see our guides to CBD and drug interactions and what the research actually shows, or browse Health Conditions.
References
- Jadoon KA, Tan GD, O’Sullivan SE. A single dose of cannabidiol reduces blood pressure in healthy volunteers in a randomized crossover study. JCI Insight. 2017;2(12):e93760. doi:10.1172/jci.insight.93760
- Sultan SR, O’Sullivan SE, England TJ. The effects of acute and sustained cannabidiol dosing for seven days on the haemodynamics in healthy men: a randomised controlled trial. British Journal of Clinical Pharmacology. 2020;86(6):1125–1138. doi:10.1111/bcp.14225
- Dujic G, Kumric M, Vrdoljak J, Dujic Z, Bozic J. Chronic effects of oral cannabidiol delivery on 24-h ambulatory blood pressure in patients with hypertension (HYPER-H21-4): a randomized, placebo-controlled, and crossover study. Cannabis and Cannabinoid Research. 2024;9(4):979–989. doi:10.1089/can.2022.0320
- Kumric M, Dujic G, Vrdoljak J, et al. CBD supplementation reduces arterial blood pressure via modulation of the sympatho-chromaffin system: a substudy from the HYPER-H21-4 trial. Biomedicine & Pharmacotherapy. 2023;160:114387. doi:10.1016/j.biopha.2023.114387
- Kumric M, Dujic G, Vrdoljak J, et al. Effects of CBD supplementation on ambulatory blood pressure and serum urotensin-II concentrations in Caucasian patients with essential hypertension: a sub-analysis of the HYPER-H21-4 trial. Biomedicine & Pharmacotherapy. 2023;164:115016. doi:10.1016/j.biopha.2023.115016
- Williams NNB, Ewell TR, Abbotts KSS, et al. Comparison of five oral cannabidiol preparations in adult humans: pharmacokinetics, body composition, and heart rate variability. Pharmaceuticals. 2021;14(1):35. doi:10.3390/ph14010035
About this article
Substantially rewritten in August 2026, consolidating our earlier reporting on CBD, blood pressure and heart rate. This update adds the HYPER-H21-4 trial results, notes the formulation and funding behind them, and sets out why CBD is not an alternative to blood pressure medication. With earlier reporting by Lydia Kariuki and Petar Petrov.
