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CBD and blood pressure

A single 600 mg dose of CBD lowered blood pressure in healthy men, but the effect faded within a week. It is untested as a treatment for hypertension.

Facts checked 13 November 20264 min readHow we research
Not enough evidence

Short studies of 600 mg a day in small groups of healthy men showed a brief drop in blood pressure that faded with repeated dosing. No trial reviewed here tested CBD as a treatment for high blood pressure.

How we grade evidence

CBD has not been shown to treat high blood pressure. In small studies of healthy men, a large single dose lowered blood pressure for a short time, mostly under stress. When the dose was repeated daily, the effect on resting blood pressure faded within a week.

What the research shows

Two small studies from the same research group are behind most claims that CBD lowers blood pressure.

  • Jadoon and colleagues (2017). Nine healthy men took a single 600 mg dose of CBD or placebo. CBD lowered blood pressure, mainly during stress tests, and raised heart rate.1
  • Sultan and colleagues (2020). Twenty-six healthy men took 600 mg a day for 7 days. The reduction in resting blood pressure seen after the first dose was lost with repeated dosing. This is called tolerance: the body adjusts and the effect wears off.1

A systematic review has since gathered the randomised trials of oral CBD and blood pressure in adults.1

Three things limit what these studies can tell us.

  • The volunteers were healthy. They did not have high blood pressure (hypertension). A treatment has to be tested in people with the condition.
  • The studies were tiny and short. Nine and 26 people, over one day and one week.
  • The effect did not last. A blood pressure treatment has to work for years. An effect that fades in a week is not evidence of that.

This is why the grade is “not enough evidence”. It is not known whether CBD does anything useful for people with hypertension.

What doses were tested

Both studies used 600 mg, as a single dose or daily for a week.1 That is four times the 150 mg a day limit for pharmacist-only (Schedule 3) CBD in Australia.2 Whether lower doses have any effect on blood pressure was not established by these studies. See does low-dose CBD work?

What Australian medical bodies say

No Australian medical body recommends CBD for blood pressure or heart disease.

  • The TGA says medicinal cannabis should be considered only when registered medicines have been tried and have failed.3
  • RACGP (the GPs’ college) calls the evidence “limited and inconclusive” and does not recommend or encourage medicinal cannabis.4
  • No cannabis medicine is registered in Australia for any heart or blood pressure condition.5

Risks to know about

People with high blood pressure or heart disease often take several medicines, and this is where the real risk lies. CBD blocks a number of liver enzymes and a transporter protein (P-gp) that the body uses to process other drugs.6

Medicine What CBD may do
Warfarin (blood thinner) Raised INR (a measure of clotting time) and bleeding have been reported with cannabinoids. Extra monitoring is advised when starting, stopping or changing dose.7
Digoxin (heart medicine) Blood levels may increase.6
Clopidogrel (anti-clotting medicine) The active form may be reduced, so it may work less well.6

No specific study of CBD with common blood pressure tablets was found in our research, so that interaction is unknown, not ruled out. See CBD drug interactions.

Other points:

  • Heart rate. The single-dose study found a rise in heart rate with 600 mg.1
  • Liver. In a 4-week study of healthy adults taking roughly 350 to 400 mg a day, 5.6% had significant rises in liver enzymes.8 The 600 mg dose used in the blood pressure studies is higher than that. See CBD and the liver.
  • Stopping proven treatment. The biggest risk is replacing a medicine that is known to prevent strokes and heart attacks with something unproven.

If you are considering it

  • Keep taking your prescribed blood pressure medicine, and talk to your GP before adding anything.
  • Ask a pharmacist to check CBD against your full medicine list, especially if you take warfarin, digoxin or clopidogrel.
  • If a prescriber suggests a CBD product, ask whether your blood pressure and blood tests should be checked more often.

See talking to your GP about CBD.

Footnotes

  1. Systematic review of randomised controlled trials of oral cannabidiol and blood pressure in adults (reports Jadoon et al., 2017 and Sultan et al., 2020). https://pmc.ncbi.nlm.nih.gov/articles/PMC13531894/ ↩ ↩2 ↩3 ↩4 ↩5

  2. Therapeutic Goods Administration. Final decision on the scheduling of low-dose cannabidiol, 2020. https://tga.gov.au/node/284859 ↩

  3. Therapeutic Goods Administration. Guidance for the use of medicinal cannabis in Australia: overview. https://www.tga.gov.au/resources/resource/guidance/guidance-use-medicinal-cannabis-australia-overview ↩

  4. Royal Australian College of General Practitioners. Medical cannabis position statement (2019 update). https://www.racgp.org.au/advocacy/position-statements/view-all-position-statements/clinical-and-practice-management/medical-cannabis ↩

  5. NPS MedicineWise. Medicinal cannabis: what you need to know. https://www.nps.org.au/professionals/medicinal-cannabis-what-you-need-to-know ↩

  6. Epidiolex (cannabidiol) US prescribing information, DailyMed, revised 2026. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=8bf27097-4870-43fb-94f0-f3d0871d1eec ↩ ↩2 ↩3

  7. Systematic review of cannabidiol drug interactions. https://pmc.ncbi.nlm.nih.gov/articles/PMC11167383/ ↩

  8. News release on Florian J et al., JAMA Internal Medicine, 2025: liver enzyme elevations in healthy adults taking cannabidiol (secondary report). https://www.eurekalert.org/news-releases/1089832 ↩

Common questions

Does CBD lower blood pressure?

Briefly, in small studies of healthy men given a large dose. A single 600 mg dose lowered blood pressure, mostly during stress tests. When 600 mg was taken daily for a week, the effect on resting blood pressure wore off.

Can I use CBD instead of my blood pressure tablets?

No study supports that. CBD has not been tested as a treatment for high blood pressure in the research we reviewed, and the short-term effect seen in healthy men faded within days. Do not stop or change a prescribed blood pressure medicine without talking to your doctor.

Is CBD safe with heart medicines?

It depends on the medicine, and a pharmacist or doctor should check. CBD can increase the effect of warfarin, may raise levels of digoxin, and may reduce the effect of clopidogrel. No specific study of CBD with common blood pressure tablets was found in our research.

Does CBD affect heart rate?

In the single-dose study of 9 healthy men, 600 mg of CBD raised heart rate while lowering blood pressure. Longer-term effects on the heart have not been established.

This page is general information, not medical or legal advice. Laws and evidence change; we show the date we last checked the facts at the top of every page. Talk to your doctor or pharmacist before starting, stopping or changing any medicine.

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