Marijuana is increasingly becoming a popular drug in the medical world. From chronic pain to inflammation and osteoarthritis, marijuana proves to alleviate the symptoms.

The legalization of marijuana is also on the rise. Countries like Canada have legalized pot while 11 States have legalized it for recreational use in the U.S. These changes present a concern for the use of marijuana.

Conventionally, marijuana is a stigmatized herb. But what is it that marijuana does to the body? When you smoke weed, many changes occur in your body. A daily marijuana smoker may not notice any physiological changes, but they do occur.

Researchers are concerned that marijuana could exacerbate heart problems for specific individuals. But are these concerns valid? What effect does marijuana have on the heart?

How Marijuana Affects Cardiovascular Function

1. Marijuana Activates the Sympathetic Nervous System

The sympathetic nervous system’s role in the control of heart rate and blood pressure. When this system is activated, there is an increase in blood pressure, heart rate, and the demand for oxygen.

The activation also causes a rise in the levels of serum norepinephrine. Norepinephrine is a stress hormone, and neurotransmitter excreted when the body is under physiological stress.

Norepinephrine plays a critical role in increasing heart rate and blood pressure. It also helps increase blood sugar and breaks down fats to make more energy available for the body.

2. It Lowers Blood Pressure

Marijuana contains Tetrahydrocannabinol (THC) which dilates blood vessels. When the diameter of the blood vessels increases, the pressure falls.

However, some reports indicate that CBD actually increases blood pressure. This is because of the compensation mechanism. When the heart senses a decrease in blood pressure, it increases its rate to compensate for the decline and to maintain balance.

3. Increases Heart Rate

The THC found in marijuana can raise the heart rate by up to 50 beats per minute. THC binds to CB1 receptors. These receptors regulate the brain nerves that modulate heart rate. They are also found in the heart muscle and around blood vessels.

By binding to CB1 receptors, THC can play a role in heart rate regulation. Studies show that this activation increases the heart rate.

4. Affects Oxygen Delivery

Smoking marijuana affects your biological oxygen availability. This is primarily because of the products of combustion. Combustion releases by-products such as carbon monoxide.

Carbon monoxide has a high affinity for hemoglobin. Hemoglobin is a protein that carries oxygen in the red blood cells. Carbon monoxide’s affinity for hemoglobin is 210 times greater than that of oxygen.

When the by-products of combustion enter the body, they outcompete oxygen for hemoglobin. This ultimately reduces the ability of the blood to deliver oxygen to the tissues.

The effects of combustion increase the risk of cardiovascular conditions. However, this only applies to smoked marijuana. This is why individuals at risk of heart diseases are advised against smoking. If they have to take marijuana, edibles would be the best option.

5. Its Effect on Arteries

Marijuana has contrasting effects on the arteries. High THC content activates CB1 receptors and in the process, increases the levels of reactive oxygen species. This can lead to oxidative stress, which may cause damage to the arterial walls.

Should this information worry marijuana users? Absolutely not. THC is only potentially harmful in high doses. For therapeutic use, microdosing with THC has shown promising benefits. 

At low doses, THC activates CB2 receptors, leading to pro-cardiovascular health effects. Microdosing on THC actually reduces plaque build-up. Such small doses have proved beneficial in treating atherosclerosis.

Contrastingly, CBD has an opposite reaction. CBD also binds to the same receptors but with a lower affinity. Interestingly, CBD counteracts reactive oxygen species by inhibiting its activation.

CBD also activates CB2 receptors and inhibits the ability of THC to activate CB1 receptors. Research evidence shows that drugs that activate CB2 receptors have pro-cardiovascular outcomes.

The activated CB2 receptors inhibit inflammation and reactive oxygen species that contribute to plaque build-up.

6. Anti-Inflammation

CBD has anti-inflammatory and antioxidant properties that are beneficial to the heart. These properties can help the heart get rid of harmful free radicals that cause plaque and ultimately, heart disease.

Studies on animals reveal that CBD improves recovery after a stroke and heart attack. CB2 receptors have anti-inflammatory capabilities and promote lipid homeostasis, which provides an anti-atherogenic effect. Alternatively,you may also try thc gummies to reduce inflammation.

7. Pro-Cardiovascular Effects

There is another beneficial endocannabinoid that is not talked about much, tetrahydrocannabivarin (THCV). At low doses, THCV blocks the activation of CB1 receptors.

By inhibiting the CB1 receptor function, THCV can reduce the sensitivity to insulin in obese individuals. This further protects such individuals from risk for cardiovascular conditions.

THCV can only activate CB1 receptors under high doses. However, few strains of cannabis have THCV levels that can activate them.


Several aspects make it difficult for researchers to study the effects of marijuana. First, the dose is an important factor. In small doses, marijuana produces different results from high doses.If you are new to weed, then simply buy weed online canada in smaller portions to reap benefits.

Second, the strain. Marijuana contains more than 100 cannabinoids and other compounds like terpenes. The concentration of the compounds differs between strains. Consequently, different strains will have different effects.

Third, the mode of delivery. Marijuana can be consumed in many ways. You can smoke it, use tinctures, tonal applications, and more. Each method of delivery has its unique effects. So, the effects of cannabis on the cardiovascular system can only be quantified after considering the above factors. When someone says marijuana is bad for your heart, the question should be which strain and what amount.


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