Pros and Cons of Medical Marijuana

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The debate over the therapeutic benefits of medical marijuana is ongoing. More than 30 states in the U.S. allow for the medical use of marijuana. And a growing number allow recreational use. However, the federal government classifies marijuana as a Schedule I controlled substance.

This federal classification makes it illegal to possess marijuana. It also limits medical studies into the potential benefits of cannabis.

The arguments for and against the legalization of marijuana are hot topics. This article explains the pros and cons of medical marijuana and the scientific evidence.

A gloved doctor filling a prescription for medical marijuana
LPETTET / Getty Images

The Pros

Americans overwhelmingly support the legalization of marijuana. In fact, according to the Pew Research Center, 91% of Americans support legalizing marijuana. Of those, 60% say it should be legal for medical and recreational use and 31% say it should be legal for medical reasons only.

Several possible health benefits of medical marijuana have been proposed:

  • Nausea: Marijuana is effective in relieving nausea and vomiting. Studies have shown that cannabis can decrease nausea caused by chemotherapy and almost eliminate vomiting.
  • Muscle relaxant: Marijuana can relieve the muscle tightness that is sometimes associated with multiple sclerosis and paralysis.
  • Appetite: Marijuana can help treat appetite loss associated with conditions like HIV/AIDS and certain types of cancers.
  • Chronic pain: Marijuana can relieve certain types of chronic pain, including neuropathic pain, which is caused by nerve damage.

And arguments in favor of using medical marijuana include:

  • It's safer: Marijuana is safer than some other medications prescribed to treat pain. For example, some people may use it instead of opioids for pain management. Opioids are highly addictive and are typically not recommended for long-term use in treating chronic pain.
  • You can use it in many ways: You do not need to smoke cannabis for its benefits. Products such as cannabidiol oil (CBD), topical pain relief treatments, edibles, and other non-smoking applications are now available.
  • You don't need to get high: As studies continue, researchers are finding benefits in the individual compounds in cannabis. When these chemicals are isolated—such as CBD has been—they can offer treatment options without the "high" produced by the compound commonly known as THC.
  • It's natural: People have used marijuana for centuries as a natural medicinal agent with good results.

The Cons

Although marijuana has many benefits, there are still some downsides. Some of the arguments from those who oppose its use include:

  • Memory: Frequent marijuana use can seriously affect your short-term memory.
  • Cognition: Frequent use can impair your cognitive (thinking) abilities.
  • Lung damage: Smoking anything, whether it's tobacco or marijuana, can damage your lung tissue. In addition, smoking marijuana could increase the risk of lung cancer.
  • Potential for abuse: Marijuana carries a risk of abuse and addiction.
  • Accidents: Marijuana use impairs driving skills and increases the risk for car collisions.
  • Illegal: Marijuana is illegal under federal law. The federal drug scheduling system classifies marijuana as a Schedule I drug in the Controlled Substances Act (CSA), alongside heroin. This classification says that the substances have no currently accepted medicinal value.

Scientific Evidence Remains Limited

In the past, clinical trials to to determine if marijuana is effective in treating certain conditions have been restrictive and limited. However, as medical marijuana becomes more common throughout the world, researchers are doing more studies.

However, expert reviews of current research continue to advocate that more studies are needed. In addition, many hurdles involve controlling the quality and dosing of cannabis with what is legally available to researchers.

One review of research noted that the long-term effects of cannabis are still unknown. Without more research into dosage and adverse effects, scientific evidence on the therapeutic effects of cannabis will remain in question.

Researchers need to evaluate marijuana using the same standards as other medications to understand whether it is valuable for managing any conditions.

Until the federal government downgrades marijuana from a Schedule I drug, widespread clinical trials are unlikely to happen in the United States.


Medical marijuana is increasingly available in the U.S. It is often used to treat chronic pain, muscle spasms, and nausea and vomiting, and to increase appetite. However, it can affect thinking and memory, increase the risk of accidents, and smoking it may harm the lungs and lead to cancer.

More studies are needed to understand the benefits of medical marijuana. However, unless the federal government removes it as a Schedule I controlled substance, research, access, and legality will remain complicated.

A Word From Verywell

There are both benefits and risks to medical marijuana. If you're considering using marijuana medicinally, don't be afraid to talk to your doctor about it. They can help you determine whether marijuana may be the proper treatment for you.

Medical marijuana remains controversial, but it is gaining traction as a legitimate recommendation for various symptoms. Even though many states have legalized cannabis for medicinal purposes and recreational use, more research is needed.

13 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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Additional Reading

By Angela Morrow, RN
Angela Morrow, RN, BSN, CHPN, is a certified hospice and palliative care nurse.