THC can increase heart rate and may make the heartbeat feel fast, pounding or irregular. Cannabis has also been associated with atrial and other arrhythmias in observational research, although having palpitations after cannabis does not prove that an arrhythmia occurred.
Quick Answer
THC can make the heart beat faster whether it comes from a prescribed medicine, a regulated nonmedical product or an illicit product. Product strength, how you took it, your other medicines and your health history all matter.
If an episode settles after taking a prescribed product, contact your prescriber or pharmacist before the next dose for individual advice. If it followed an illicit or unknown product, avoid taking more and contact a poison center or urgent medical service for advice if you are concerned about the exposure.
When to Get Emergency Help
Call your local emergency number if palpitations will not stop or occur with chest pain, shortness of breath, fainting or feeling as though you might pass out. Also call if the person collapses, has a seizure, has trouble breathing or cannot be woken. Do not drive yourself.
If chest pain, shortness of breath or near-fainting occurred and the episode has fully stopped, seek urgent medical assessment today.
Child may have swallowed a THC product? Contact your local poison center immediately, even if the child seems well. Call emergency services first if the child has any of the emergency signs above.
Prescribed Cannabinoid Medicine and Illicit Cannabis
Using a cannabinoid medicine for an ongoing illness
Some cannabinoid medicines have defined uses. In the United States, prescription dronabinol may be used for certain cases of chemotherapy-related nausea and vomiting or appetite loss with weight loss in AIDS. In the UK, NICE recommends a supervised trial of a THC:CBD spray for selected adults with multiple sclerosis and moderate to severe spasticity. Prescription cannabidiol for certain seizure disorders is a separate medicine containing CBD.
If palpitations follow a new prescription or dose change and have settled, call your prescriber or pharmacist before your next dose. Have the product name, strength, dose and time taken ready. Bring your full medication list, including supplements. Your care team can consider side effects, interactions and the risks of changing treatment for the underlying illness.
Using illicit or unregulated cannabis
With an unregulated edible, vape or concentrate, the amount of THC and the ingredients may be uncertain. A familiar-looking package may give little information about what was actually taken. A regulated nonmedical product can also cause palpitations if it contains THC.
If symptoms develop, avoid taking more, stay somewhere safe and do not drive. Tell the clinician or poison center what you know about the product, the time taken and any alcohol, stimulants or other substances used. If you suspect K2 or Spice, tell them explicitly. These synthetic products can cause serious poisoning.
How the Situation Changes With Age and Health History
Babies and children
A child may be unable to describe a racing heart. If a child might have swallowed a THC gummy, drink or other product, call a poison center immediately. Unusual sleepiness, difficulty waking or trouble breathing after a suspected exposure needs immediate attention. Follow the emergency guidance above.
Teenagers
Ask calmly what they took and when. Ask about vapes, edibles, alcohol and energy drinks, since details can help a clinician or poison center advise you. Seek emergency help if the heartbeat keeps racing or the teen has warning symptoms.
Adult women and men
The same warning signs apply. Tell your clinician about heart disease, previous arrhythmias and any medicines you take. If you are pregnant or breastfeeding, speak with your maternity team about any cannabis exposure and about safer ways to manage the symptoms you were treating.
Older adults
If you feel lightheaded after taking a product, sit or lie down somewhere safe. A clinician can review blood pressure, heart history and potential interactions, particularly if you take several medicines or recently changed a dose.
How Does THC Affect the Heart?
THC, or tetrahydrocannabinol, is the principal intoxicating cannabinoid associated with the “high” produced by cannabis.
Its acute effects can include changes in the autonomic nervous system, which regulates functions such as heart rate and blood pressure.
Shortly after THC exposure, some people may experience:
- a faster heart rate;
- a pounding or forceful heartbeat;
- changes in blood pressure;
- dizziness;
- anxiety or panic;
- trembling; or
- increased awareness of normal heartbeats.
The American Heart Association has described THC as capable of stimulating sympathetic nervous-system activity, which can increase heart rate and cardiac oxygen demand.
The rhythm may simply be sinus tachycardia — the heart’s normal pacemaker beating faster in response to THC, anxiety or another trigger. An ECG is required to determine whether the rhythm is sinus tachycardia, atrial fibrillation, SVT, premature beats or something else.
Can Cannabis Trigger a Heart Arrhythmia?
Cannabis use has been associated with several arrhythmias in medical studies, particularly atrial arrhythmias.
Reported rhythms include:
- atrial fibrillation;
- atrial flutter;
- atrial tachycardia;
- supraventricular tachycardia;
- PACs and PVCs; and
- more serious ventricular arrhythmias in uncommon reports.
A 2025 systematic review and meta-analysis of observational studies found an association between cannabis exposure and atrial arrhythmias.
However, this does not mean cannabis inevitably causes arrhythmia, nor does it prove causation for every individual.
Association Is Not the Same as Proof of Cause
Cannabis research is complicated by differences in THC strength, frequency of use, smoking versus ingestion, concurrent tobacco, alcohol or other drug exposure, and incomplete product labeling.
The current evidence supports taking cardiovascular symptoms after cannabis seriously, while avoiding the stronger claim that every palpitation after cannabis represents a THC-induced arrhythmia.
Who May Be at Greater Cardiovascular Risk?
Extra caution is appropriate for people with:
- known atrial fibrillation or another arrhythmia;
- structural heart disease;
- cardiomyopathy;
- previous heart attack;
- coronary artery disease;
- heart failure;
- an inherited cardiac channel disorder;
- unexplained fainting;
- significant cardiovascular risk factors; or
- a history of cannabis-associated cardiac symptoms.
Recent cardiology reviews advise particular caution in patients with underlying cardiovascular disease because the consequences of tachycardia or an arrhythmia may be more important in these groups.
Delta-8 THC vs Delta-9 THC: Are They Different for Palpitations?
They are chemically related but not identical.
| Delta-9 THC | Delta-8 THC | |
|---|---|---|
| What is it? | The main naturally occurring intoxicating THC in cannabis. | A psychoactive THC isomer found naturally only in small amounts. |
| Intoxicating? | Yes. | Yes. |
| Common products | Flower, concentrates, vapes, edibles and beverages. | Often gummies, vapes and other hemp-derived products. |
| FDA safety status | Most consumer cannabis products are not FDA-approved medicines. | Delta-8 consumer products have not been evaluated or approved by FDA for safe use. |
| Heart-safe alternative? | No. | No evidence supports considering delta-8 a cardiovascular-safe substitute. |
“Hemp-Derived” Does Not Mean Non-Psychoactive or Risk-Free
Delta-8 THC is psychoactive and intoxicating.
Because naturally occurring concentrations are very low, commercial delta-8 is commonly produced by chemically converting hemp-derived CBD.
FDA has raised concerns about variable concentrations, inaccurate labeling, manufacturing by-products and contaminants in delta-8 products.
Can Delta-8 THC Cause Heart Palpitations?
Delta-8 THC should not be assumed to be harmless to the cardiovascular system simply because it may be marketed as milder than traditional cannabis.
FDA describes delta-8 as psychoactive and intoxicating, similar to delta-9 THC, and has received reports of significant adverse events involving delta-8 products.
Reported effects have included:
- anxiety;
- dizziness;
- confusion;
- tremor;
- vomiting;
- hallucinations; and
- loss of consciousness.
Specific cardiovascular effects of delta-8 are less well studied than delta-9 THC, so we should not invent a precise arrhythmia risk.
If a racing or irregular heartbeat develops after delta-8 use, the same principle applies: assess the actual rhythm rather than assuming the product is safe because it came from hemp.
Does the Way Cannabis Is Used Change the Risk?
Yes. Route of administration changes how quickly THC takes effect, how predictable the exposure is and what additional risks are present.
Smoking cannabis
Inhaled THC reaches the bloodstream quickly, so changes in heart rate and intoxication can begin rapidly.
Cannabis smoke also contains many of the same harmful combustion products found in tobacco smoke, creating additional cardiovascular and respiratory concerns.
Vaping or concentrates
Vape oils and concentrates may contain very high THC concentrations. Product composition can vary, particularly with unregulated products.
High-potency exposure may make adverse effects such as anxiety, rapid heartbeat and excessive intoxication more likely.
Edibles
Edibles have delayed and less predictable effects compared with inhaled cannabis.
CDC notes that intoxicating effects may take 30 minutes to two hours to appear and can last longer than expected.
Multiple substances
Alcohol, nicotine, caffeine and other recreational or stimulant drugs may complicate the cardiovascular response.
When several substances were used together, it can be difficult to know which one produced the palpitation.
Why Can Edibles Cause Unexpected Palpitations?
Edibles deserve their own explanation because people sometimes consume additional THC before the first dose has fully taken effect.
CDC notes that edible cannabis:
- may take 30 minutes to two hours to produce intoxicating effects;
- can produce effects lasting longer than expected, and Health Canada notes that full effects can take up to four hours;
- can have unpredictable THC concentrations; and
- can result in excessive intoxication when more is consumed before the first effect appears.
Excessive THC exposure can be associated with:
- fast heart rate;
- increased blood pressure;
- extreme anxiety;
- panic;
- confusion;
- paranoia;
- hallucinations; and
- severe nausea or vomiting.
A Racing Heart After an Edible May Be THC + Anxiety — But Do Not Assume
Anxiety can substantially increase heartbeat awareness, but a persistent fast or irregular rhythm should be medically assessed when symptoms are significant or do not settle.
Can THC-Induced Anxiety Cause Heart Palpitations?
Yes.
THC can cause anxiety, panic and paranoia in some people, particularly with larger or unexpectedly potent exposures.
Panic activates the sympathetic nervous system and may cause:
- a racing heartbeat;
- pounding in the chest;
- rapid breathing;
- trembling;
- sweating;
- dizziness;
- chest tightness; and
- a feeling that something dangerous is happening.
Symptoms alone may not distinguish sinus tachycardia from SVT, atrial fibrillation or another rhythm. A persistent or markedly irregular episode is best assessed with an ECG rather than diagnosed as panic from the sensation alone.
See our guide to anxiety and heart palpitations .
Can Cannabis Cause a Slow Heart Rate?
Most acute THC discussions focus on increased heart rate, but cannabis exposure has also been associated less commonly with bradycardia and conduction abnormalities in medical reports.
This is one reason it is better not to reduce cannabis cardiovascular effects to the simple statement that “marijuana always makes the heart race.”
If you develop a markedly slow pulse together with dizziness, fainting, weakness or other symptoms, medical assessment is appropriate.
See our guide to bradycardia and heart palpitations .
What About CBD?
CBD and THC are different cannabinoids.
CBD does not usually produce the same intoxication as THC, but that does not make every commercial CBD product medically proven or free of risk.
Product labeling can be inaccurate, and some products may contain THC or other cannabinoids in amounts that differ from what is expected.
CBD should also not be promoted as a treatment for heart palpitations or arrhythmias without evidence.
What About Synthetic Cannabinoids Such as K2 or Spice?
Synthetic cannabinoids are not the same as cannabis.
Products sometimes sold as “K2,” “Spice” or “synthetic marijuana” contain laboratory-made chemicals that act strongly on cannabinoid receptors.
Their effects can be unpredictable and substantially more dangerous. Reported adverse effects include:
- very rapid heart rate;
- severe agitation;
- confusion;
- hallucinations;
- vomiting;
- seizures;
- serious cardiovascular complications; and
- death.
Do Not Treat Synthetic Cannabinoids as “Just Strong Marijuana”
Severe symptoms after K2, Spice or another synthetic cannabinoid product deserve urgent medical evaluation because toxicity can be unpredictable and potentially life-threatening.
What Should You Do if Cannabis Causes Heart Palpitations?
If symptoms are mild, you are fully alert and there are no emergency warning signs:
- Avoid taking more THC while you are having symptoms. If it is a prescribed medicine, contact your prescriber or pharmacist for advice about the next dose.
- Sit or lie somewhere safe.
- Do not drive or operate machinery.
- Avoid adding caffeine, nicotine, alcohol or other stimulants.
- Use slow, comfortable breathing if anxiety is contributing.
- Drink normal amounts of fluid if you may be mildly dehydrated and have no fluid restriction.
- Note the product, dose if known, time taken and when symptoms started. Keep the package if you have it.
- If possible, note whether the pulse feels regular or irregular.
Do Not Try to Treat the Rhythm With More Substances
Do not take extra beta-blockers, antiarrhythmics, potassium, high-dose magnesium, sedatives or another person’s medicine in an attempt to counteract THC.
If the rhythm is sustained, markedly irregular or associated with significant symptoms, medical assessment is safer than attempting to “balance” the cannabis effect yourself.
See how to stop heart palpitations safely for general self-care guidance.
Should You Use Cannabis Again if It Caused Palpitations?
Recurrent cardiovascular symptoms after cannabis exposure are worth discussing with a healthcare professional rather than repeatedly reproducing the exposure to see what happens.
This is particularly important if you have:
- known heart disease;
- a previous arrhythmia;
- unexplained fainting;
- significant chest discomfort;
- repeated episodes of rapid or irregular heartbeat; or
- a family history of serious rhythm disorders or sudden cardiac death.
The purpose of evaluation is to determine whether the episode was sinus tachycardia, premature beats or a genuine arrhythmia rather than assuming all future exposure will produce the same response.
How Are Cannabis-Associated Palpitations Evaluated?
Evaluation is similar to other palpitation presentations but should include a clear substance-use history.
Important history
Your clinician may ask:
- which cannabis or cannabinoid product was used;
- whether it contained delta-8, delta-9 or another cannabinoid;
- whether it was smoked, vaped or eaten;
- when symptoms began relative to use;
- how long the palpitations lasted;
- whether the pulse felt regular or irregular;
- whether caffeine, nicotine, alcohol or another substance was also used;
- whether chest pain, dizziness, breathlessness or fainting occurred;
- current medicines and supplements; and
- known cardiovascular disease.
ECG
A 12-lead ECG can determine whether a currently symptomatic patient has sinus tachycardia, premature beats, AF, SVT, bradycardia or another electrical abnormality.
If palpitations repeatedly occur after cannabis but stop before an ECG is obtained, longer monitoring may sometimes be appropriate.
Ambulatory monitoring
Holter, patch or event monitoring may be considered if episodes recur and the rhythm has not been documented.
Blood tests
Depending on the clinical picture, clinicians may assess:
- electrolytes;
- thyroid function;
- blood count;
- kidney function; or
- other tests suggested by the symptoms.
Further cardiac testing
Echocardiography or other testing may be considered when there is abnormal ECG, recurrent arrhythmia, known cardiovascular disease or another reason to suspect structural heart disease.
If your resting ECG was normal but the symptoms keep recurring, see heart palpitations despite a normal ECG .
Dr. Albana’s Note
When a patient tells me, “My heart started racing after cannabis,” I first want to know exactly what was taken, how it was used and what happened afterward. An edible that became much stronger than expected is a different situation from a few skipped beats after inhaled cannabis, and a delta-8 product may not contain exactly what the label suggests. I also ask about caffeine, nicotine, alcohol and other drugs because combinations can complicate the reaction. THC can certainly produce sinus tachycardia and anxiety, but I do not assume that every rapid or irregular sensation is simply panic. If symptoms are recurrent, sustained or truly irregular, documenting the rhythm with an ECG or monitor gives us a much safer answer.
When Should You Make a Medical Appointment?
Arrange medical evaluation when:
- palpitations repeatedly occur after cannabis or THC;
- episodes last several minutes or longer;
- the heartbeat feels markedly irregular;
- you develop dizziness or unusual weakness;
- you repeatedly become short of breath;
- you have known cardiovascular disease;
- you have a history of AF, SVT or another arrhythmia;
- you nearly fainted or fainted during an episode;
- symptoms have changed substantially from previous reactions; or
- you are concerned that a product contained an unexpected or synthetic substance.
For broader triage guidance, see when to worry about heart palpitations .
Urgent Warning Signs
Call your local emergency number if palpitations will not stop or occur with chest pain, shortness of breath, fainting or feeling as though you might pass out. See the emergency and poison center guidance above.
Most Asked Questions
Can cannabis cause heart palpitations?
Yes. THC can acutely increase heart rate and may cause pounding, racing or fluttering sensations. Cannabis has also been associated with arrhythmias in observational research, although symptoms alone cannot prove which rhythm occurred.
Can THC make your heart race?
Yes. THC can stimulate the sympathetic nervous system and commonly produces an increase in heart rate. Anxiety or panic may intensify the sensation.
Can delta-9 THC cause palpitations?
Yes. Delta-9 THC is the main intoxicating cannabinoid in cannabis and can increase heart rate and heartbeat awareness. Persistent or markedly irregular symptoms should be medically evaluated.
Can delta-8 THC cause heart palpitations?
Delta-8 is psychoactive and should not be considered a heart-safe alternative to delta-9 THC. Cardiovascular effects are less well studied, and commercial products can vary in strength and composition.
Is delta-8 safer for the heart than delta-9?
There is not enough evidence to say that delta-8 is cardiovascularly safer. FDA has not evaluated or approved commercial delta-8 products for safe use and has raised concerns about adverse events, manufacturing and product variability.
Can cannabis cause atrial fibrillation?
Observational studies and recent meta-analyses have found an association between cannabis exposure and atrial arrhythmias, including atrial fibrillation. These studies cannot prove that cannabis directly caused every episode, but recurrent AF or palpitations after use deserve evaluation.
Why does an edible make my heart pound?
Edibles can produce delayed and sometimes unexpectedly strong THC effects. Excess THC may increase heart rate and can also provoke anxiety or panic, both of which may produce a pounding heartbeat.
How long can palpitations from an edible last?
There is no fixed duration. Edible THC has delayed and longer-lasting effects compared with inhaled cannabis, and the response varies with amount, product strength, food intake, other substances and individual sensitivity. Persistent or concerning symptoms need medical assessment.
Can cannabis cause skipped beats?
Premature atrial and ventricular beats have been reported in association with cannabis use. A skipped sensation after cannabis can also be increased awareness of the heartbeat, so an ECG or monitor is needed to establish the rhythm.
Can cannabis cause a slow heartbeat?
Although increased heart rate is more commonly discussed, bradycardia and conduction abnormalities have also been reported. A slow pulse accompanied by dizziness, fainting or weakness should be evaluated.
Can THC anxiety feel like a heart arrhythmia?
Yes. THC-induced panic may cause racing heartbeat, rapid breathing, chest tightness and dizziness. These symptoms can resemble an arrhythmia, so persistent or clearly irregular palpitations should not automatically be attributed to anxiety.
Should I take a beta-blocker to stop THC palpitations?
Do not take an extra beta-blocker or another heart-rhythm medicine unless your clinician has specifically prescribed an individualized plan for that situation. Treatment depends on the actual rhythm, blood pressure and clinical condition.
What should I do if my heart races after cannabis?
Avoid taking more, sit somewhere safe and do not drive. Call your local emergency number if palpitations will not stop or occur with chest pain, shortness of breath, fainting or feeling as though you might pass out. If symptoms settle and it was a prescribed medicine, call your prescriber or pharmacist before the next dose.
Can a normal ECG rule out cannabis-related arrhythmia?
Not if the episode ended before the ECG was recorded. A normal ECG shows the rhythm during that recording. Recurrent intermittent symptoms may require longer monitoring.
Related Heart Palpitation Guides
Medical References
- NHS guidance on heart palpitations and emergency signs
- FDA overview of approved cannabinoid medicines and their uses
- NICE recommendations on cannabis-based medicinal products
- Health Canada guidance on delayed effects of edible cannabis and risks of unregulated products
- Poison Control guidance after a child eats a cannabis edible
- CDC guidance on cannabis during pregnancy and breastfeeding
- Centers for Disease Control and Prevention. Cannabis and Heart Health. Updated February 15, 2024. CDC .
- Centers for Disease Control and Prevention. Cannabis and Poisoning. Updated February 15, 2024. CDC .
- Centers for Disease Control and Prevention. Cannabis Frequently Asked Questions. CDC .
- Page RL 2nd, Allen LA, Kloner RA, et al. Medical Marijuana, Recreational Cannabis, and Cardiovascular Health: A Scientific Statement From the American Heart Association. Circulation. 2020;142:e131–e152. American Heart Association .
- U.S. Food and Drug Administration. 5 Things to Know About Delta-8 Tetrahydrocannabinol. FDA .
- Joglar JA, et al. Cannabis Use and Atrial Arrhythmias: A Systematic Review and Meta-analysis of Large Population Studies. 2025. PubMed .
- Richards JR, et al. Arrhythmias and Cannabis Use: A Comprehensive Overview. Heart Rhythm O2. 2025. PubMed .
- Mahmoud AN, et al. Cannabis Effects on Cardiovascular Health: Current Evidence, Gaps in Knowledge, and Future Research Directions. Trends in Cardiovascular Medicine. 2026. PubMed .
About the Medical Team
Dr. Albana Greca, MBBS, MMedSc
Family Physician / General Practitioner
Dr. Albana Greca has more than 20 years of experience in primary care, general medicine, chronic disease management, prevention, patient education and digital health.
Dr. Benard Shehu, MBBS, MS
Cardiologist
Dr. Benard Shehu has more than 19 years of cardiovascular experience, including clinical experience relevant to arrhythmias and cardiovascular disease.
Related medical guide: Medications, Supplements & Substances That May Trigger Heart Palpitations.