marijuana vasoconstriction

How Medical Marijuana Acts as a Vasodilator

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Updated on January 5, 2020. Medical content reviewed by Dr. Joseph Rosado, MD, M.B.A, Chief Medical Officer

While many patients and caregivers are familiar with the most common side effects of medical weed, such as giddiness and hunger, most are unaware of the beneficial effect of tetrahydrocannabinol (THC) as a vasodilator, which influences the treatment of several conditions, including glaucoma.

What Is a Vasodilator

A vasodilator is any substance that causes vasodilation, which is the widening of your blood vessels to improve blood flow to other parts of your body, such as your heart. While vasodilation also occurs naturally within the body, such as when you’re feeling faint, vasodilators are a part of modern medicine.

For example, you can treat high blood pressure with vasodilators — by expanding your blood vessels, your blood pressure decreases. Unlike prescription medications, however, medical cannabis is a natural vasodilator that interacts with your body’s receptors to initiate vasodilation.

Why Medical Cannabis Acts as a Vasodilator

Due to federal and state laws, it’s difficult for researchers to provide a specific answer as to why medical cannabis acts as a vasodilator. Like many of its effects, however, scientists believe it’s tied to the endocannabinoid system (ECS), which features cell receptors that bind with cannabinoids, like THC, to create a reaction.

As an example, consider this interaction of the ECS and cannabinoids in pain management. You consume medical marijuana, such as through smoking, and your body begins to process the medical weed. During that process, cannabinoids activate ECS receptors throughout your body to regulate reactions, such as chronic pain.

How Medical Marijuana-Induced Vasodilation Treats Conditions

Because of limited research opportunities, scientists are aware of only some of the instances where medical marijuana-induced vasodilation treats conditions and helps patients resume their daily lives or regain a sense of normalcy in their day-to-day activities.

Conditions that respond well to vasodilation include:

  • Glaucoma: A primary side effect of glaucoma is pressure. Due to the ineffective drainage of fluid, eye pressure builds up, which can lead to blindness from optic nerve damage. With the natural vasodilation of medical weed and supportive lifestyle changes, intraocular pressure can decrease to a manageable level — and without the severe side effects of prescription treatments.
  • High Blood Pressure: As the name reveals, high blood pressure or hypertension involves the increased demand placed on your heart and arteries to pump blood throughout your body. Like glaucoma, many patients use medical pot as a vasodilator and complement to their treatment plan, which will likely include diet and exercise.
  • Nail-Patella Syndrome: One symptom of nail-patella syndrome is glaucoma. By incorporating medical marijuana into your treatment plan, you can lower your blood pressure by natural means, which will then offset and manage your intraocular pressure. As medical pot treats several other side effects of nail-patella syndrome, like chronic pain, it delivers a multi-faceted treatment plan.

With more research, scientists expect to discover additional beneficial uses of medical weed as a vasodilator.

Benefits of Medical Weed-Induced Vasodilation

Incorporating medical weed into your treatment plan for its role as a vasodilator offers several benefits, including:

  • A more natural and effective approach
  • Fast- or long-acting medicating options
  • Strains that ease multiple symptoms
  • Fewer and less severe side effects than prescription drugs

If you’re considering using medical pot because it’s a vasodilator, talk to your medical marijuana doctor first.

Learn More About Medical Cannabis and Vasodilation

At, we give families and patients valuable, up-to-date information on medical marijuana. From research studies and legislation changes to qualifying conditions and side effects, we compile and deliver it in a compact, easy-to-understand form for you and your family.

To learn more about medical cannabis and vasodilation, explore our resource library and blog!

Many are familiar with the most common side effects of medical weed, like giddiness & hunger; most are unaware of its beneficial effect of vasodilation.

Marijuana induced Reversible Cerebral Vasoconstriction Syndrome

Nnamdi Uhegwu

1 JFK New Jersey Neuroscience Institute at Seton Hall University, Edison, NJ

* Authors contributed equally

Asif Bashir

1 JFK New Jersey Neuroscience Institute at Seton Hall University, Edison, NJ

* Authors contributed equally

Mohammed Hussain

1 JFK New Jersey Neuroscience Institute at Seton Hall University, Edison, NJ

* Authors contributed equally

Haitham Dababneh

1 JFK New Jersey Neuroscience Institute at Seton Hall University, Edison, NJ

* Authors contributed equally

Sara Misthal

1 JFK New Jersey Neuroscience Institute at Seton Hall University, Edison, NJ

Aaron Cohen-Gadol

2 Goodman-Campbell Brain & Spine & Indiana University Department of Neurological Surgery, Indianapolis, Indiana


Reversible cerebral vasoconstriction syndrome (RCVS) is a transient multifocal arterial vasoconstriction and dilatation. The term was proposed by a panel of experts1 as a unifying term for a variety of a syndromes characterized by cerebral vasospasms and resultant clinical manifestations of cerebral ischemia. These syndromes include Call–Fleming syndrome, drug-induced cerebral angiopathy, benign angiopathy of the CNS, postpartum cerebral angiopathy, and migrainous vasospasm. Drug abuse, especially cannabis, is an important etiologic factor for RCVS. It is one of the most widely used recreational substances in the world, considered by many consumers as a relatively safe drug with few significant side-effects.2 Cannabis contains 9-tetrahydrocannabinol (THC), which is rapidly absorbed when smoked, reaching a peak plasma concentration at 10–30 min, and is lipid soluble with a large volume of distribution.3 Cannabinoids bind to cannabinoid receptors, CB1 in the central nervous system and CB2 in the immune system.

Case Summary

A 59-year-old left-handed African–American male with a past medical history of diabetes and hyperlipidemia presented with an episode of acute aphasia, right hemiparesis, and left gaze deviation. A noncontrast CT scan of the head showed microvascular ischemic white matter changes and CT angiography showed patent cerebral vasculature with diffuse narrowing of cerebral vessels ( Figure 1 ). Coagulation profile was normal. Urine toxicology was positive for THC. Additional parameters, such as a urine drug screen, hypercoagulable panel, and alcohol screen, were negative. An MRI of the brain without contrast demonstrated acute infarcts in the left thalamus and left parietal lobe posteriorly ( Figure 2 ).

On admission, the patient was started on aspirin and received physical therapy. He showed marked improvement with mild residual dysarthria. The patient continued to improve and was discharged on Hospital Day 4 with a National Institutes of Health Stroke Scale of 0. A repeat CT angiography at discharge showed patent cerebral vasculature with improved flow in the bilateral higher convexities ( Figure 3 ).


Cardiovascular side effects of marijuana have been documented, including tachycardia, hypertension, postural hypotension, and increased levels of carboxyhemoglogin.4 There have been several reports of stroke following cannabis use.5 Since 1987, fewer than 25 cases of ischemic stroke associated with cannabis smoking have been published.6–8 Postulated mechanisms for such stroke include cerebral vasospasm,9–11 vasculitis, and postural hypotension with impairment in cerebral autoregulation of the brain blood flow.8, 12

In addition to the direct central nervous system action, marijuana may augment stroke onset via other mechanisms, such as causing cardiovascular effects, which include tachycardia,13 hypertension, and postural hypotension.14 Furthermore, smoking marijuana increases carboxyhemoglobin, which reduces oxygen transportation capacity and leads to the onset of stroke.15 Additional causes of stroke associated with cannabis are due to an increased risk of myocardial infarction and paroxysmal atrial fibrillation.5 Concomitant alcohol consumption or unusually high consumption of cannabis has been regarded as possible precipitating factors for acute ischemic strokes.7,8 ‘Cannabis arteritis’ that pathologically resembles Buerger’s disease is found in patients that are regular cannabis users and only moderate tobacco smokers.14

Ischemic stroke studies have suggested that cannabis associated strokes were more frequent in vertebrobasilar territory, suggesting susceptibility of posterior circulation. 6,8 Mesec et al reported arterial spasms on transcranial ultrasound and MRA in a patient with cannabis related stroke.9 Ducros et al also reported RCVS with cannabis abuse.11 Mathew et al used transcranial ultrasound to demonstrate reduced middle cerebral artery (MCA) velocities but normal systemic pressures after cannabis use, suggesting the possibility of impaired cerebral autoregulation.16 Furthermore, Herning et al examined blood flow velocity in the anterior and MCAs using transcranial Doppler sonography in marijuana users (who were stratified into light, moderate, and heavy smokers).12 It was found that the pulsatility index and systolic velocity were significantly increased in marijuana users when compared with control subjects and these increases persisted in the heavy marijuana users after a month of monitored abstinence.12

Marijuana induced Reversible Cerebral Vasoconstriction Syndrome Nnamdi Uhegwu 1 JFK New Jersey Neuroscience Institute at Seton Hall University, Edison, NJ * Authors contributed equally