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Medical Marijuana (Cannabis) FAQs


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What is cannabis?

Cannabis is a flowering plant with fibrous stalks. The leaves, flowers, and roots are used for medicinal purposes. On the mature plant, the leaves and flowers are covered with trichomes - tiny glands of resinous oil containing cannabinoids and terpenes that, when consumed, can provide physical and psychoactive effects.
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What is medical cannabis?

Also called “medical marijuana,” medical cannabis is cannabis and cannabinoids (chemical compounds in the plant) that can be medically recommended to treat certain conditions and symptoms, such as nausea and vomiting associated with chemotherapy, and pain that can be associated with numerous conditions.

To learn more, watch Ask an MS Expert: Medical Cannabis and MS.
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What are cannabinoids?

Cannabinoids are the chemical compounds secreted by cannabis flowers. There are also compounds called terpenes – chemical compounds that give cannabis its unique aroma. The concentrations and combinations of the cannabinoids and terpenes vary from plant to plant and among the different strains of cannabis. When inhaled, consumed as an edible, or used on the skin as a topical preparation, the cannabinoids bind to cannabinoid docking sites or receptors in the human body and alter nerve transmission in the brain.
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What is the difference between THC and CBD?

The two major cannabinoids in cannabis that have been studied are:
  • THC (tetrahydrocannabinol, also known as delta-9-tetrahydrocannabinol), is thought to be the most psychoactive substance (i.e., a substance that changes brain function and alters perception, mood, consciousness or behavior) in cannabis. The concentration of THC in cannabis varies between 1% and 24%.
  • CBD (cannabidiol) is the major non-psychoactive cannabinoid found in cannabis. The concentration of CBD in cannabis is typically less than 1%, but many strains have higher CBD concentrations.
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What kind of cannabis products are there in the U.S.?

Botanicals are a variety of cannabis products that are derived from the cannabis plant. Cannabis can be taken via inhalation (smoked plant or vaporized extracts), orally (oils, tinctures, extracts, “edibles”), or as a topical application (lotions and salves).  These products vary in their concentration and proportions of cannabinoids and may be labeled with this information.

Synthetic cannabinoids are compounds that made in the laboratory rather than from the plant. The FDA has approved 2 synthetic cannabinoid products with specific rules for prescribing:
  • Dronabinol (Marinol®) –consists of synthetic THC suspended in sesame oil and sold in capsules approved for the treatment of chemotherapy-induced nausea and vomiting and as an appetite stimulant in patients with AIDS.
  • Nabilone (Cesamet®) –  mimics THC and comes in capsules for the treatment of chemotherapy-induced nausea and vomiting
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Will cannabis help my pain? Spasticity? Bladder symptoms?

There have been numerous studies conducted to evaluate the effects of cannabinoids on MS-related pain, spasticity, and bladder symptoms. Most studies involved relatively small numbers of people with MS and the outcome measures varied among studies. However, reviews of published studies have generally shown that synthetic cannabinoids favorably impact symptoms of pain and spasticity. Less is known about the impact of inhaled or ingested botanical cannabis on MS symptoms.  
For more information about research evidence in MS, download the 2023 Cannabis Use in MS Summary.
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What are the risks of using cannabis?

There are side effects associated with the use of botanical cannabis and synthetic cannabinoids including: mental confusion, cognitive impairment, anxiety and/or paranoia, nausea, vomiting, dry mouth, dry eyes, sedation, increased appetite, headache, impaired balance and coordination, and elevated heart rate. There are also potential risks to the lungs if cannabis is smoked.
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Can I travel with medical cannabis?

Currently cannabis is federally designated as a schedule 1 drug, making it federally illegal to transport cannabis on flights, or across state lines.  For more information, visit Americans for Safe Access online.   
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What is the Society’s position on the use of medical cannabis in MS?

The Society supports the rights of individuals living with MS to collaborate with their healthcare providers in determining if medical cannabis is an appropriate treatment option, in compliance with state laws.  

Although there are no cannabis-based FDA-approved medications to treat MS or its symptoms, some clinical trials have shown that non-smoked CBD/THC modestly improves reported spasticity and pain in people with MS.

The Society: 

  • Supports the removal of barriers for long-term safety and efficacy research of medical cannabis and derived compounds for the symptoms of MS and eventual creation of evidence-based guidelines in MS care
  • Supports informed, open and shared decision-making between people with MS and their healthcare professionals. We believe that this engaged partnership leads to treatment adherence, self-advocacy, high satisfaction with care and better health outcomes
  • Supports the availability of resources to promote safe and legal access for therapeutic use and research
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Does the Society advocate for access to medical marijuana?

The National MS Society supports the ability of people living with MS to make informed choices about their treatments with their MS health care providers, including the use of medical cannabis. Recognizing that additional research is still needed, we are evaluating ways we can remove the barriers to allowing research on medical cannabis at the federal level. We advocate legalizing medical cannabis at the state level.

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What is the basis for the Society’s position?

In 2014, the American Academy of Neurology (AAN) released a “Summary of evidence-based guideline: Complementary and alternative medicine in multiple sclerosis.” The guideline was created by a panel of medical experts who evaluated all published research studies. Among studies of several forms of cannabis and its derivatives evaluated by the panel, evidence suggests:
  • Oral cannabis extract and synthetic THC (tetrahydrocannabinol—a major active component of cannabis) are probably effective for reducing patient-reported symptoms of spasticity and pain, but not MS-related tremor or spasticity measurable by tests administered by the physician.
  • Sativex oral spray (GW Pharmaceuticals) is probably effective for improving patient-reported symptoms of spasticity, pain and urinary frequency, but not bladder incontinence, MS-related tremor or spasticity measurable by tests administered by the physician.
The AAN findings state that smoked cannabis research studies have not produced enough evidence to assess its safety or effectiveness for treating MS symptoms including spasticity, pain, balance, posture and cognition changes.

The AAN further notes: "Oral cannabis extract, THC and Sativex are not currently approved by the FDA for use by people with MS. The FDA has approved only two forms of marijuana for medical use: dronabinol (Marinol) and nabilone (Cesamet). Dronabinol also is approved for loss of appetite associated with weight loss in patients with AIDS. At this time, the drugs are not approved for other uses.

Cannabis is a complex substance which may contain many different components affecting the body. Production of marijuana for medical use is not standardized or supervised by the FDA or any other agency for its quality, purity, or specific ingredients, hence, the effects of different batches of marijuana may not be the same."

The guideline notes that cannabis usage, as with any therapy, may result in both potential benefits and potential side effects. For these cannabis derivatives, the most commonly reported side effects were dizziness, drowsiness, difficulty concentrating and memory disturbance. The guideline also points out that the long-term safety of cannabis use for MS symptom management is not yet known.


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