Does CBD Affect Heart Rate? We Review the Science and Conduct Our Own Experiments to Find Out It’s well known that THC increases heart rate and blood pressure, and that this is likely related to CBD oil is made from cannabis plants but won’t make you high. Still, this natural supplement could interact with some heart medicines. Find out what you need to know before you try CBD oil for heart failure.
Does CBD Affect Heart Rate? We Review the Science and Conduct Our Own Experiments to Find Out
It’s well known that THC increases heart rate and blood pressure, and that this is likely related to THC’s anxiety and psychosis-inducing effect. But what about CBD, THC’s cannabinoid cousin? CBD has an opposite effect on anxiety, psychosis, and brain function as THC: it reduces anxiety, strengthens brain connections, and reduces symptoms of psychosis.
Could it reduce heart rate as well?
There are several studies that explore CBD’s effect on heart rate, and we go over them thoroughly in this article. But we decided that wasn’t enough, and we put the science to the test on our favorite guinea pigs (us).
I tested CBD’s effect on my resting heart rate, my heart rate after cardio, and my heart rate after a (particularly extreme) sauna session. Keep reading to find out the results.
Does CBD affect heart rate?
Yes, CBD may reduce heart rate under stressful conditions, but the evidence is mixed on whether CBD has any effect on heart rate in non-stressful conditions.
What the science says
Here’s a review of all the major studies conducted on CBD and heart rate:
- In one 2009 study published in the British Journal of Pharmacology , rats were subjected to stressful conditions that increased their blood pressure and heart rate. After being given a dose of CBD, their heart rate and blood pressure decreased.
- In this 2017 randomized, double-blind, placed controlled clinical trial published in the Journal of Clinical Investigation ,CBD was found to reduce blood pressure in healthy male participants but increase heart rate compared to the placebo group.
- In a 2011 study published in the Journal of Neuropsychopharmacology , participants were given either a large dose of CBD prior to a public speaking event or a placebo. The researchers reported lower blood pressure, heart rate, and anxiety levels for the CBD group.
So, the two studies which applied CBD in stressful conditions (one in rats and one in humans) both found reduced blood pressure and heart rate, but the study which applied CBD in non-stressful situations found only a reduction in blood pressure and an increase in heart rate.
Does CBD only affect heart rate in stressful conditions?
This suggests that CBD may only reduce heart rate if heart rate has otherwise been increased by stressful conditions. This makes sense because increased heart rate and blood pressure is a result of autonomic arousal, aka the “fight or flight” response that is activated upon stress. Autonomic arousal is also the mechanism behind anxiety and panic attacks, and CBD is well-known as an effective anxiety reliever: one 2019 study in The Permanente Journa l and another in the Journal of Neurotherapeutics both found that CBD reduced anxiety.
So, CBD anxiolytic (anti-anxiety) effects are likely related to its potential ability to reduce heart rate.
CBD and THC: two very different cannabinoids
It’s important to note that, while CBD and THC are both derivatives of cannabis, when it comes to acute cardiovascular function they appear to have opposite effects: THC increases autonomic arousal, whereas CBD reduces it; CBD may reduce heart rate, but THC is known to increase heart rate.
This key difference in the two cannabinoids — in how they affect the nervous system — explains why one, THC, is associated with increased anxiety and psychosis, while the other, CBD, is associated with the opposite.
The difference also provides further reason to believe that CBD and THC may function best in combination, especially given the substantial evidence indicating that CBD may reduce negative side-effects of THC (including on brain function). For instance, in this September 2019 study just conducted by the University of Western Ontario , they found that CBD blocked the psychiatric side-effects of THC. PhD candidate and head researcher Roger Hudson explained that “ CBD was also able to reverse the anxiety-like behaviour and addictive-like behaviour caused by the THC.”
What about CBD’s overall effect on the cardiovascular system?
As with CBD’s effect on heart rate, this is a very open question. Bottom line is: we don’t know, because little research has been done on CBD’s effect on the cardiovascular system.
Large studies on marijuana use and cardiovascular function have found little definitive evidence of a positive or negative effect, and since CBD has much less of an impact on the cardiovascular system than THC it’s reasonable to assume that CBD has minimal impact on cardiovascular health overall.
But there’s more to it than that, and two recent studies have indicated that CBD may in fact have a positive effect on cardiovascular health.
Two studies: CBD reduces heart inflammation
In this 2013 review of several studies published in the British Journal of Clinical Pharmacology , CBD was found to positively influence white blood cell survival and migration related to heart disease. The researchers concluded that “ A common theme throughout these studies is the anti-inflammatory and antioxidant effect of CBD. In the heart, in vivo CBD treatment protects against ischaemia-reperfusion damage and against cardiomyopathy associated with diabetes.”
The second 2016 study published in the Journal of Molecular Medicine CBD reduced markers of inflammation in individuals with autoimmune myocarditis, a condition which causes inflammation of the heart.
So, while it’s far too early to determine how exactly CBD influences cardiovascular function, there is promising evidence that CBD’s known anti-inflammatory properties apply to the heart as well, and that CBD can potentially reduce heart-related inflammation.
The CBD heart rate experiment
So, there’s the hard science on how CBD affects heart rate. Now, for the fun part: I put it to the test. To measure my heart rate I used a FitBit, and for each test I took 40 mg of NuLeaf Naturals organic full-spectrum CBD oil.
Given that the science indicates different results in different conditions, we tested CBD’s effect on my heart rate in three different conditions: resting, during exercise, and after a sauna session.
Test 1: Resting heart rate
This is the simplest test we conducted: each day over a period of three days, at the same time (2:00 PM) each day, we measured my heart rate without CBD, and then I took a 40mg dose of NuLeaf Naturals organic full-spectrum CBD oil, we waited 30 minutes, and we measured my heart rate again. We then took the average of all three measurements. Here are the results:
|Day 1||Day 2||Day 3||Average|
As you can see, I did experience a modest reduction in heart rate after taking the CBD, though the reduction wasn’t consistent and it wasn’t outside the normal variation in my heart rate.
Test 2: Heart rate while exercising
For this test, I ran for 20 minutes on a treadmill at a constant rate (5mph), got off the treadmill and measured my heart rate, then took a dose of CBD, waited 30 minutes, got back on the treadmill at the same rate for the same time (20 mins) and measured my heart rate again. As with the first test, we did this three times over three days and took the average of all three.
|Day 1||Day 2||Day 3||Average|
Again, we found a relatively small reduction in heart rate, though this reduction was consistent across all three days.
Test 3: Heart rate after sauna
This test was a bit more complicated. I’m a regular sauna user, and fewer things jack your heart rate up more than the sauna. I was curious if CBD would have any effect on how quickly my heart rate returned to normal after a sauna session.
Here’s the test: I did a 20 minute sauna session at 200 degrees (brutal) without CBD then measured my heart rate immediately after getting out, and then again every three minutes to determine how long it returned to normal. The next day I repeated the same process but with CBD.
|Immediately after sauna||3 minutes after sauna||6 minutes after||9 minutes after||12 minutes after|
The results for this one are interesting: my heart rate was higher immediately after getting out with CBD, but fell faster with the CBD and reached a lower point 9 minutes after.
None of the results of my experiments were SUPER eye-catching, but as you can see from the charts I did experience a modest but noticeable reduction in heart rate after taking CBD across all three experiments. However, these tests also were all under non-stressful conditions: even the ones involving cardio and sauna ultimately aren’t a great test of the “fight or flight” response. The increased heart rate and blood pressure during physical activity is a physical adaptation that’s different from the increase you’d see with anxiety.
A better test, and one that I will try to conjure up over the next few weeks, is testing my heart rate under anxiety-inducing conditions, and then testing with CBD under the same conditions to see if there’s any difference. Stay tuned, folks!
FAQ on CBD and Heart Rate
Does CBD affect heart rate medication?
Actually, CBD is metabolized by the same liver enzymes as 60% of medications on the market, so it can block these enzymes and allow more of the medication into your system. If you are on any medications, including heart rate medication, discuss CBD with your doctor before using.
Does CBD increase your heart rate?
One study we reviewed did record an increase in heart rate after consumption of CBD (though the blood pressure of the participants was lowered). However, other studies (and our own experiments) indicate that CBD is more likely to decrease heart rate.
Does vaping CBD increase heart rate?
Vaping CBD does allow you to consume more concentrated doses of CBD, which may have more of an affect on heart rate than other methods. But the evidence indicates that even at more potent doses CBD is more likely to decrease than increase your heart rate.
CBD Oil and Heart Failure
Could CBD oil ease your heart failure symptoms or help you manage your condition? This herbal supplement is sold over the counter and may be marketed with various health claims, but heart experts aren’t so sure it’s worthwhile or even safe if you have heart failure.
“Heart failure patients should know that while CBD has been touted as a wonder compound and seems to be in almost everything these days, it has never been shown to have any significant cardiovascular benefits in human studies,” says Scott Lundgren, DO, a transplant cardiologist at Nebraska Medicine in Omaha.
What Is CBD Oil?
CBD oil contains cannabidiol, an herbal liquid supplement made from the cannabis plant. It doesn’t have the same effect on the brain as THC, another compound found in cannabis that gives you a “high” when smoked or eaten, says Larry Allen, MD, associate division head for clinical affairs in cardiology at University of Colorado Anschutz Medical Campus.
“There are no known cardiovascular benefits for cannabis or cannabidiol, and there may even be some adverse effects, so people should not take these products and think that it will have positive effects on their cardiovascular health,” says Allen, who’s also co-author of the American Heart Association’s statement on all cannabis products.
In 2018, the FDA approved the first oral, purified CBD drug, Epidiolex, to treat seizures in two rare forms of epilepsy. Two synthetic versions of cannabiinds are also approved: dronabinol (Marinol, Syndros) for treatment of nausea during cancer chemotherapy and nabilone (Cesamet) to treat weight loss associated with AIDS. Marinol is synthetic THC
Some of CBD’s proven benefits in other health conditions may be intriguing to people living with heart failure, Allen says.
“Does it stimulate your appetite? Yes. Do people gain weight if they take it? Possibly true. Patients with severe heart failure do have cachexia,” or severe weight loss and muscle wasting, he says. “One could argue that people with nausea, lack of appetite, or who are losing weight could think CBD would help them. People with heart failure have a fair amount of discomfort, including edema [swelling] and somatic or pain-related issues, so you could think CBD has a role.”
But there isn’t really any evidence to prove that it will relieve heart failure symptoms or be safe to use if you have heart failure, he adds.
What We Know About CBD
Some research suggests that CBD oil may improve some heart-related symptoms:
- A very small study conducted in 2017 in England found that CBD improved resting blood pressure and blood pressure spikes related to stress in people without heart conditions.
- Various studies in animals have shown that CBD could improve vasorelaxation, or opening of arteries for better blood flow, as well as reduce inflammation. A small clinical trial from Mexico studying CBD in people with heart failure hasn’t reported any results yet.
- A large study of more than 161,000 people hospitalized for heart failure who had used marijuana found that they had, on average, a lower risk of death and shorter hospital stays. But this doesn’t necessarily mean CBD oil would have the same benefit.
It’s illegal in the U.S. to market CBD by adding it to any food or calling it a dietary supplement. Also, although the FDA has approved a few CBD drugs to treat certain diseases, don’t expect CBD sold over the counter to be safe or beneficial for heart failure, Lundgren says.
“CBD oil may not have the same properties, and it can actually cause gastrointestinal distress like diarrhea or cause decreased appetite. CBD products can include unknown ingredients and may not be accurately labeled,” he says.
When you use CBD oil, your liver breaks it down. During this process, it could interfere with your medications for heart failure or other heart conditions. “CBD has known interactions with warfarin, certain statins, calcium channel blockers, beta-blockers, and nitrates. Just because a supplement is ‘natural’ doesn’t mean that it is safe,” Lundgren says.
CBD May Have Health Risks
CBD oil must be studied in randomized clinical trials on people, not animals, before it can be considered safe or effective for heart failure, Lundgren says. Until that happens, he advises against buying or using CBD. “There is some evidence that CBD can cause liver injury as well as lead to male infertility issues. When consumed with alcohol, individuals may experience increased drowsiness, which can lead to household injuries.”
If you have heart failure, you might feel like you’re taking control of your own care by trying herbal treatments that don’t require a prescription. To be safe, talk to your cardiologist first: Ask questions about CBD oil and make decisions together about using this or any other supplement, Allen says.
“CBD products cost money and can distract you from taking prescribed treatments for heart failure that are evidence-based. They could do indirect harm to people with heart failure. . We already have a half-dozen treatments for heart failure symptoms and to help you live longer.”
Larry Allen, MD, MHS, University of Colorado Anschutz Medical Campus.
Scott Lundgren, DO, Nebraska Medicine.
FDA: “What You Need to Know (And What We’re Working to Find Out) About Products Containing Cannabis or Cannabis-derived Compounds, Including CBD,” “FDA Approves First Drug Comprised of an Active Ingredient Derived from Marijuana to Treat Rare, Severe Forms of Epilepsy,” “FDA and Cannabis: Research and Drug Approval Process.”
JCI Insight: “A single dose of cannabidiol reduces blood pressure in healthy volunteers in a randomized crossover study.”
Oxidative Medicine and Cellular Longevity: “Therapeutic Applications of Cannabinoids in Cardiomyopathy and Heart Failure.”
Cannabis and Cannabinoid Research: “An Update on Safety and Side Effects of Cannabidiol: A Review of Clinical Data and Relevant Animal Studies.”
ClinicalTrials.gov: “Cannabidiol in Patients With Heart Failure in AHA/ACC Stages A-C (CAPITAL-AC).” NCT03634189.
Journal of Cardiac Failure: “Marijuana Use is Associated with Better Hospital Outcome in Patients with Acute Heart Failure: A Propensity Match Analysis from National Inpatient Database.”