How does cannabis affect blood pressure?
Copy article link to clipboard.
Link copied to clipboard.
- Does marijuana lower or raise blood pressure?
- What are the cardiovascular effects of cannabis?
- Weed and blood pressure medication
- Other effects of weed on blood pressure
Since smoking a joint can lead to a relaxing high, you might wonder about cannabis use and its effect on blood pressure. We know that weed can make your eyes red , but does it also raise or lower blood pressure, or does it not have any effect at all? If you have high blood pressure, is marijuana safe to consume?
Here we’ll address how smoking weed, including medical marijuana, could factor into your blood pressure levels.
Does marijuana lower or raise blood pressure?
To answer this question, we should focus on two of the primary cannabinoids present in cannabis : cannabidiol (CBD) and tetrahydrocannabinol (THC). Both may exert an influence on blood pressure levels.
Dr. Bonni Goldstein, a medical adviser to Weedmaps and the director of Canna-Centers in Lawndale, California, outlined the potential effects of THC on blood pressure:
“THC can affect blood pressure depending on the dose, the route of administration, a person’s experience with THC, and a person’s underlying health. Healthy volunteers that took THC had an increase in heart rate and decrease in blood pressure. In studies where people used THC while lying down, they had elevated blood pressure. When they stood up, their blood pressure dropped and they experienced low blood pressure.”
These sudden drops in blood pressure, also known as white outs or green outs, may indeed be linked to cannabis use. Dr. Melanie Bone, a board-certified OB-GYN and cannabis specialist who practices in West Palm Beach, Florida, told Weedmaps that “cannabis may cause a drop in blood pressure on standing — known as postural hypotension.” This type of drop in blood pressure is not desirable, as it can cause vertigo and even fainting. So, when we talk about “lowering blood pressure,” we do not necessarily consider that effect beneficial to health.
Both THC and CBD may lower blood pressure in different ways. However, neither CBD nor THC should be considered a medical treatment for high blood pressure. Photo by: Gina Coleman/Weedmaps
And how does CBD affect blood pressure? The consensus is that CBD tends to relax the blood vessels and decrease anxiety, which ultimately leads to a lowering of blood pressure. This type of blood pressure reduction is more favorable, as it is associated with decreased levels of anxiety. Both THC and CBD may lower blood pressure in different ways. However, based on available research, neither CBD nor THC should be considered a medical treatment for high blood pressure.
What are the cardiovascular effects of cannabis?
Another frequently asked question about cannabis and cardiovascular health is: can weed cause a heart attack?
First, let’s again distinguish between the cannabinoids THC and CBD. For example, CBD oils containing trace levels of THC may have very different effects than smoking a high-THC strain of marijuana. Various studies have indicated that THC may have detrimental effects on cardiovascular health, whereas CBD could be helpful to the heart.
Goldstein added, “CBD does not appear to have the same risks for the heart as THC and in fact, appears to be somewhat cardioprotective.” To support this assertion, Goldstein cited a 2010 study published in the Journal of the American College of Cardiology in which researchers concluded that CBD has therapeutic potential in treating complications of diabetes, as well as some cardiovascular disorders. Most notably, CBD could reduce inflammation, a condition that can ultimately damage the blood vessels, arteries, and vital organs. So, if you apply CBD oil to your skin or swallow a few tablespoons, the impact could differ greatly than if you smoked a blunt.
To this point, there is some research that suggests smoking THC could directly or indirectly lead to a heart attack. One 2019 study titled “The Cardiovascular Effects of Marijuana: Are the Potential Adverse Effects Worth the High?” and published in the Journal of the Missouri State Medical Association showed that some people experienced a heart attack within an hour of smoking cannabis.
Bone, however, argued, “On careful study, many of the patients also smoked cigarettes and were obese, making it hard to draw absolute conclusions. Also, the observations were made on cannabis of unknown origin, not cannabis from a dispensary.” The fact that the cannabis did not come from a registered dispensary is significant, as there is no available lab testing to determine what other compounds may have been present.
The bottom line is that there have been studies demonstrating a questionable association between smoking weed and having a heart attack, and more research is necessary.
Weed and blood pressure medication
You might also be wondering, what if you’re smoking weed while taking blood pressure medication? Will there be an adverse reaction? If you are smoking THC-rich cannabis and taking medication for high blood pressure, the answer is that there could be.
Goldstein explained, “Smoking cannabis can be harmful for those with heart disease or hypertension since the smoke contains carbon monoxide. This gas binds to the hemoglobin in red blood cells, displacing oxygen off of the red blood cells which results in less oxygen going to the body’s tissues, including the heart. People with heart disease or high blood pressure should avoid smoking.”
Instead, Goldstein recommends other methods of cannabis use, such as sublingual tinctures or edibles, which she says are safe to use if someone is on blood pressure medication. Further, Bone stressed that people who use cannabis and are on blood pressure medications need to be mindful of the possibility of an interaction with other prescription medications. This means monitoring blood pressure and reporting any dizziness to your doctor, who can adjust your dosages accordingly.
People who use cannabis and are on blood pressure medications need to be mindful of the possibility of an interaction with other prescription medications. Photo by: Gina Coleman/Weedmaps
In particular, the blood thinner warfarin was shown in a 2017 study published in the journal Epilepsy & Behavior Case Reports to interact with cannabidiol (CBD) in certain epileptic individuals . In line with Bone’s advice, researchers concluded that patient lab work should be monitored closely.
While it is possible for warfarin and other medications to interact with cannabis, there are no guarantees, and the 2017 study focused on patients with epilepsy rather than on the general population. As Dr. Bone reported, “In my private practice, I have not encountered a significant negative interaction between blood pressure medication and cannabis.”
Other effects of weed on blood pressure
There may be other effects of marijuana on blood pressure that health practitioners have yet to discover. All potential effects depend on the individual’s existing health problems, especially co-morbid conditions such as diabetes and obesity.
Can people without these conditions safely indulge in marijuana? A healthy individual’s body may appear as a well-oiled machine, but Bone disputes that analogy, pointing out that, “Unlike a car, where we replace the brakes or tires, the heart never gets a vacation and the blood vessels need to keep working forever. And the nervous system, which directs the show like a conductor, is on duty 24/7.”
Moderation, then, may be key in integrating a cannabis regimen into your healthcare plan. Consult with your physician before you begin using cannabis or CBD products and discuss any medications you are currently taking.
Learn how cannabis affects blood pressure and what questions you should ask your doctor before starting a regimen.
Cannabis and its impact on high blood pressure
Given the increasing prevalence of hypertension at a time when states are liberalizing cannabis laws, people want to know: what are the effects of cannabis on blood pressure? Does it lower blood pressure? The answers largely depend on who you ask or what study you read.
One in three adults in the U.S. has high blood pressure, a condition known as hypertension. Left unmanaged, it can lead to cardiovascular disease, which is characterized by an increased risk of stroke, heart attack, and even heart failure. A number of factors, including poor diet, stress, physical inactivity, alcohol, and tobacco use increase the risk of developing hypertension.
Some of the effects of cannabis on blood pressure, particularly the acute effects, are well understood and documented. However, research studies describing other effects, especially long-term adverse or positive effects, are limited, and often plagued by poor study design or the fact that findings from animal studies don’t always neatly transfer to human subjects.
Further, many research findings are highly generalized, focusing on THC while neglecting consideration of the numerous other cannabinoids. Logically, a cannabis strain high in the psychoactive cannabinoid THC would yield different results from a strain high in the largely non-intoxicating cannabinoid CBD.
Perhaps most frustrating, published studies investigating differences between consumption methods – such as the effects of smoking cannabis versus ingested edibles – are essentially nonexistent.
With these limitations in mind, here is what we do know.
Short-Term vs. Long-Term Effects of Cannabis Consumption
Does cannabis raise blood pressure? Studies suggest shortly after consumption, occasional users will experience a mild to moderate dose-dependent increase in blood pressure and heart rate, followed by a modest hypotensive effect (a decrease in blood pressure). The onset of peak effects like elevated heart rate and blood pressure occur within 10 to 15 minutes after consumption.
Users can develop a tolerance to the initial effects over a period of a few days to weeks, and repeated use has been associated with lowered heart rate and blood pressure immediately following consumption. Anecdotally, many people report that cannabis helps them maintain healthy blood pressure levels, an effect supported by research studies.
Here’s an interesting piece of “non-trivial trivia” you can use to impress friends at your next cannabis-inspired intellectual discussion: posture during consumption may influence blood pressure. Suppose you’re sitting or lying on your couch – your blood pressure will temporarily increase immediately following consumption. Once you stand up, blood pressure will drop. In fact, if you stand up suddenly, blood pressure could drop significantly enough to induce enough lightheadedness to make you feel like you’re about to faint (don’t worry, it’s unlikely you’d actually pass out).
On the other hand, if you’re standing up when you imbibe, blood pressure may decrease without ever initially increasing. However, there isn’t a lot of published data verifying this effect. (If you’ve done your own comparative measurements, feel free to share in the comments section below!)
Cannabis and Stroke or Heart Attack
As far as serious adverse risks, a UC San Francisco longitudinal Coronary Artery Risk Development in Young Adults (CARDIA) study analyzing data from 3,617 African American and Caucasian adults over a 15 year period found there was no long-term causal link between cannabis consumption and the risk of heart attack or stroke.
However, there are a limited number of animal studies and human case reports that suggest a link between acute intoxication and stroke or heart attack. But, these findings have been called into question by a 2006 report published in the Forensic Science, Medicine and Pathology Journal: “Despite the drug’s extreme popularity, reports of cannabis-related stroke and myocardial infarction are so rare as to still be reportable.”
Further, human case reports often don’t take into account that in these rare events, people may have consumed cannabis in conjunction with alcohol, tobacco, or stimulants contemporaneously or shortly before the incident.
Nonetheless, a Harvard Medical School study concluded that for an hour after consuming cannabis (especially in at-risk populations; e.g. seniors), the odds of suffering a heart attack increases by five times. Risk returns to normal within two hours. Notably, sex carries a comparable risk increase. This begs the question: does combining cannabis and sex exponentially increase one’s chances of a heart attack? We’re eagerly awaiting a follow-up study from Harvard to answer this question.
Is There a Link Between Cannabis and Hypertension Treatment?
It’s long been established that the body’s endocannabinoid system (whose naturally occurring chemicals behave similarly to cannabinoids found in cannabis) play an important role in regulating many of the body’s key physiological functions, including cardiovascular function.
A growing body of research shows that anandamide – the body’s naturally occurring version of THC – relaxes blood vessels, the implication being that by allowing blood to flow more freely, anandamide helps lower blood pressure.
Notably, the National Institute on Alcohol Abuse & Alcoholism published a report concluding “endocannabinoids tonically suppress cardiac contractility in hypertension,” and that “targeting the endocannabinoid system offers novel therapeutic strategies in the treatment of hypertension.”
The degree to which the endocannabinoid system plays a role in regulating blood pressure has long inspired researchers to examine if we could treat hypertension by manipulating the endocannabinoid system.
However, we’re not there yet. Remarkably, despite the fact that cannabinoids have been studied for their potential as antihypertensive agents since the 1970s, no cannabinoid-based medications have been officially approved to treat hypertension. Moreover, despite an ever-growing body of anecdotal evidence and numerous studies suggesting the regular use of cannabis does appear to produce long-term lower blood pressure levels, we lack the sort of rigorous human studies that would allow physicians to confidently say, “Use cannabis to treat your hypertension!”
As we continue to develop a better understanding of the cannabinoid receptor system’s role in cardiovascular regulation, we’ll soon be able to more confidently identify the therapeutic role for cannabinoids in blood pressure control.
Does cannabis lower blood pressure? Learn about the effects of cannabinoids on blood pressure, and find out if it can be used as a hypertension treatment.