Does CBD Lower Heart Rate? Evidence-Based Insights

Cannabidiol (CBD) is a chemical compound naturally found in hemp and marijuana. CBD can be extracted and is popularly added to oral products, morning smoothies, and even sports bras. Why are so many people crazy about CBD? Well, a lot of that is still under investigation, but it seems the botanical may have multiple influences on the body and is even hypothesized to contribute to the maintenance of homeostasis.

One of the purported benefits of CBD is that it lowers heart rate, benefitting cardiovascular health. Read on to learn what science has to say about CBD, heart health, and how it may affect heart rate.

Understanding heart rate

Your heart rate refers to the number of times your heart beats in a minute. Though heart rate varies, a healthy heart beats about 60–100 times per minute when at rest. The rate of your heartbeat depends on many factors like age, health, and physical activity.

The heart rate is one of the measures doctors use to assess heart health and function. A heart that beats more than 100 times per minute at rest is considered too fast and called tachycardia.

It’s normal to have a fast heart rate when you’re stressed or exercising; your heart is pumping faster to move oxygen-rich blood throughout your body. However, a fast heart rate or heart palpitations from unknown causes can be concerning and need a medical evaluation.

A fast heartbeat may cause symptoms such as:

• Dizziness or lightheadedness
• Shortness of breath
• Chest pain
• Fatigue
• Heart palpitations

These symptoms may mean you have an abnormal heart rhythm — also known as an arrhythmia — that needs medical attention. Some causes of tachycardia can be signs of serious cardiovascular health conditions like coronary artery disease and atrial fibrillation.

On the flip side, if your heart rate is less than 60 beats per minute at rest, your heart rate is considered too slow, medically called bradycardia. If you work out regularly or you’re an athlete, you may naturally have a slower heart rate. However, a slow heart rate combined with other symptoms like dizziness or fatigue is cause for concern and should be evaluated by your doctor.

Can CBD lower heart rate?

Research into CBD and the possible health benefits are in the early stages and any claims are based on incomplete evidence. Anyone with an abnormally high heart rate should talk to their doctor before trying any compounds like CBD to manage their condition.

But what’s the connection between CBD, heart rate, and cardiovascular health? It all starts with the endocannabinoid system (ECS), the cell-signaling system that plays a role in maintaining your body's balance, or homeostasis. More specifically, the ECS interacts with the body’s immune and nervous system and may influence mood, appetite, pain, and sleep.

Though researchers are still learning about the scope of activity of ECS, one of the theories is that it helps regulate various internal body processes, such as temperature and immune system activity, helping maintain balance or homeostasis. Additionally, ECS signaling is involved in regulating stress and anxiety, supporting cognitive function, circadian rhythms, and more. CBD is a plant cannabinoid that interacts with the ECS and is believed to contribute to the modulation of processes influenced by ECS function.

For the heart, animal studies indicate that CBD may relax the arteries, potentially making it easier for the heart to pump blood. The plant chemical also appeared to protect the heart following a heart attack in animal models. It’s theorized that the anti-inflammatory properties of CBD may play a role in the potential benefits for cardiovascular health.

However, CBD doesn’t seem to have much of an effect on heart rate. A 2017 systematic review and meta-analysis of multiple animal studies reported that both acute and chronic CBD administration has no effect on heart rate. Additionally, a 2020 review article published in the International Journal of Molecular Science that included human and animal studies reported that CBD only seems to lower heart rate under states of stress.

In fact, CBD may increase heart rate. A small 2017 study published in JCI Insights noted an increase in heart rate in the participants following CBD administration before and after induced states of stress.

Best forms of CBD

Since it’s not clear whether CBD can lower heart rate, it’s not known what forms are best. If you’re taking CBD to support health, you should know the different forms available since it may play a role in CBD bioavailability.

CBD can come in capsules, tinctures, gummies, and sprays. CBD tinctures and sprays are suggested to be more bioavailable than CBD capsules since they bypass first-pass metabolism in the liver. If you prefer CBD capsules over liquid forms, water-soluble CBD formulations are reported to be more bioavailable than oil-based CBD preparations, and both types are reported to absorb better when taken with food.

In addition to form, CBD products come with different types of CBD preparations. This is important if you have concerns about the presence of tetrahydrocannabinol (THC), the cannabinoid compound in the marijuana plant that is associated with intoxicating effects. CBD doesn’t make you high, but some types of CBD preparations may contain minuscule amounts of THC.

Broad-spectrum CBD extracts have no THC, while full-spectrum CBD products have less than 0.3% THC. For the record, both marijuana and hemp plants contain CBD and THC, but hemp plants regularly have negligible amounts.

Most CBD products use hemp-derived CBD extracts, so they naturally have little to no THC. The 2018 Farm Bill made hemp legal in the United States. Since hemp may contain some THC, the bill legalized the sale of hemp products to the general public as long it has less than 0.3% THC.

Some CBD products may contain CBD isolate, a pure form of CBD that has no other cannabinoid compounds or terpenes.

How much CBD should I use?

Researchers have yet to determine any specific CBD dosage for use in support of any health condition. Studies use varying dosages, making it difficult to determine how much to use.

The National Library of Medicine says doses up to 200 milligrams a day for 13 weeks appear to be safe. If you’re thinking of taking CBD, talk to your doctor first to discuss the right amount for you.

Safety and side effects

CBD is likely safe when taken at the right dose. Taking high doses of CBD may increase liver enzyme production and may negatively affect liver health.

However, even at recommended doses, CBD can cause unpleasant side effects such as:

• Lightheadedness
• Diarrhea and gastrointestinal upset
  
• Dizziness
• Low blood pressure

CBD can also affect how the liver metabolizes drugs like blood thinners, immunosuppressants, and antibiotics, potentially affecting drug levels in the blood. If you take any medication — prescription or over-the-counter (OTC) — talk to your doctor or pharmacist about potential interactions.

Because it’s not known how CBD may affect a fetus or baby, people who are pregnant or breastfeeding shouldn’t take CBD unless under the direction of their doctor.

Should you try CBD to lower your heart rate?

If you have concerns about a fast heart rate, talk to your doctor. They can identify the cause of your condition and provide a personalized treatment plan to lower your heart rate. There’s very little evidence to show that taking CBD can lower your heart rate, and it’s even possible it may increase it.

When to speak to your doctor

You should always talk to your doctor about dietary supplements before trying them. Though readily available, dietary supplements contain active ingredients that may affect how the body functions and interacts with medications.

Additionally, CBD products aren’t tested for quality, safety, or effectiveness by the FDA, and it’s up to the manufacturer to ensure their product is safe and contains the ingredients listed on the label.

Your doctor can provide guidance on whether you can benefit from CBD and what types and doses are best for you.

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