Cannabidiol (CBD) is a legal cannabinoid used in many countries as a medicine and health food supplement. It is taken by consumers for a wide range of reasons from arthritis to neurological disorders. In this article I shall be summarising some of the scientific research relating to CBD and its effects on blood pressure.
Two studies, that focused solely on blood pressure in men, both showed that the administration of CBD significantly reduced resting blood pressure and reduced blood pressure increases when the participants were subjected to stress. One of the two studies demonstrated that the benefits on resting blood pressure diminished after long term usage of CBD, however, the ability to reduce the impact of stress on blood pressure did not diminish after prolonged use. The study also found that the internal carotid artery diameter increased more after 7 days of CBD consumption than it did after a singular dose (1). The other study was focused more on one large dose of CBD and its impact on blood pressure, showing it reduced blood pressure and the impact of stress on blood pressure (2).
Human studies, other than the two mentioned above, are hard to find. There are however a number of studies performed on animal models regarding CBD and blood pressure. One study on rodents, reviewed in 2011, found that CBD treatment for 14 days did not affect blood pressure or heart rate in any way (3). This information is promoted by the World Health Organisation (WHO). In their Critical Review Report on Cannabidiol they state that “In contrast to THC, CBD has no effect on heart rate or blood pressure under normal conditions” (4). They do however note that CBD has a protective effect on stress related blood pressure increase, this data was sourced from a meta-analysis from 2017 (5).
Further study is most definitely needed into the effects of CBD on blood pressure. Some studies seem to imply that CBD does reduce blood pressure in mammals, but many other studies and reviews find that CBD only has an effective role in reducing stress related blood pressure increases. It certainly does not provide stronger results than blood pressure medications. CBD also interacts with the cytochrome-p450 class of enzymes in the liver that are vital in drug metabolism, and so CBD may adversely affect regular blood pressure medication.
Written by Joseph Wardle Bsc, Msc.