The Legality of Using Medical Marijuana for Pain Relief

Marijuana is increasingly being prescribed and used for a variety of medical reasons, including pain relief. But its use is controversial, and in the United States—as in every other country in the world—it continues to be illegal under federal law. Despite this fact, over half the states in the U.S. have approved the prescribing of marijuana for medical purposes.

Here are some frequently asked questions about the use of marijuana for pain relief.

What Is Medical Marijuana?

Some trimming medical marijuana

Uriel Sinai / Getty Images

Cannabis sativa, the Latin name for marijuana, is an herb that has been used for thousands of years to treat many different symptoms. It's also one of the 50 fundamental herbs used in traditional Chinese medicine (an alternative therapy). The active ingredient in medical marijuana, also known as medical cannabis, is tetrahydrocannabinol (THC). The herb cannabis/marijuana is labeled as a Schedule I substance according to the US Federal Government, indicating that (legally) it has no known medicinal properties or uses.

There is also a synthetic version of THC called Marinol. Marinol is a Schedule III substance.

What Is Medical Marijuana Used to Treat?

Depending on the source of information, there are dozens of symptoms, as well as diseases and conditions that feature those symptoms, which can be treated and improved using medical marijuana. However, there's not much evidence to prove how it works; most of the evidence is anecdotal in nature. In many cases, professionals will tell you that it works only because people think it will work: the mind tells the body that pain has been relieved, or nausea has vanished. Others, usually proponents of the use of medical marijuana, will tell you that there is plenty of evidence.

Among the symptoms that some believe may be relieved are:

  • Pain
  • Nausea, vomiting, and diarrhea
  • Improving appetites for cancer and AIDs patients
  • Reduction of pressure in the eyes
  • Depression
  • Cramps
  • Panic attacks
  • Itching

Among the diseases it might be used to treat:

  • Chronic pain
  • Glaucoma (relief of eye pressure)
  • Dystonia
  • Multiple sclerosis
  • HIV
  • Rheumatoid arthritis
  • Sleep apnea
  • Tourette's syndrome

How Is It Administered?

The administration of the THC in marijuana is actually at the center of much of the controversy over its use.

In the past, medical marijuana had to be smoked in order for people to feel any benefit (or a high)—and because people were smoking it, it was controversial. But today, ingesting marijuana has become safer through the development of inhalers which vaporize the herb and allow the THC to be breathed in. Marijuana can also be swallowed through the use of capsules, and it's effective if eaten as an ingredient in brownies, cookies, cakes or other forms of sweets.

What Side Effects Might Patients Experience by Using Medical Marijuana?

Among the negative side effects that have been reported are impaired memory and coordination.

But remember, there hasn't been a great deal of formal research into these side effects, nor have they been formally documented any more than the benefits have been documented.

What Other Names Are Used for Medical Marijuana?

Both the herb and the synthetic versions of marijuana and THC go by a variety of names. Some names used for non-medical marijuana include pot, grass, weed, Maryjane, hash, or hashish.

While hemp is a form of cannabis, it's not the same form that can be smoked to create a high. The plant itself may be used for clothing or woven materials, but it's not used medicinally or for a high.

There are also brand names for the synthetic versions of THC. In the US and Canada, the synthetic drug is called Marinol. In Mexico, the United Kingdom, Canada, and the United States, a synthetic brand is called Cesamet.

Where Is Marijuana Legal or Illegal?

The prescribing, or use of, medical marijuana in the United States is illegal according to federal law. However, 33 states (plus Washington, DC) have legalized the use of medical marijuana, with varying restrictions. The Marijuana Pro Con website maintains information about states and their laws.

Similar to the United States, medical marijuana is illegal in all other countries. However, there are places in many of those countries where provinces or states have also tried to override federal policies, including:

  • Canada
  • The synthetic form of cannabis/THC can be prescribed and used in Belgium, Austria, Netherlands, the UK, Spain, Israel, Finland, and other countries, as well as in some of the United States where the herbal form is still illegal.
  • Many people believe marijuana is legal in the Netherlands (Amsterdam), but officially it is illegal. Its use by citizens of the Netherlands is not prosecuted. It is illegal for tourists to purchase it.

What Are the Objections to Making It Legal Everywhere Else?

The first is that marijuana is used recreationally for a high, and is smoked to gain that high. Legalizing it creates a slippery slope—and possibly new smokers—and many governments just don't want to go there.

Secondly, there are major questions about the control of the supply as compared to its benefits. Because of the ways and places it's grown and sold, there is no way to guarantee that one dose of marijuana is equal to the next.

Questions about quality, including the percent of marijuana (combined with fillers) in one dose, mean that consistency is in question. Even if one marijuana dose is compared to an equal dose, the potency and purity will not be the same. That makes it very difficult to do accurate research into its effectiveness, and impossible to label it accurately.

How Can You Obtain Marijuana for Medical Use?

See any of the sources below. There is a wealth of information available, but not all of it is objective or accurate.

Be sure any of the websites you review follow the guidelines for credible, reliable health information online. Among the most important guidelines is the one that encourages you to find the most current information. The research, laws, and use of medical marijuana change frequently.


The following are some great resources for more information about medical marijuana and the current state of its use and legality throughout the country:

4 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.
  1. United States Drug Enforcement Administration. Drug Scheduling.

  2. U.S. Food and Drug Administration. Marinol.

  3. Volkow ND, Baler RD, Compton WM, Weiss SR. Adverse health effects of marijuana useN Engl J Med. 2014;370(23):2219–2227. doi:10.1056/NEJMra1402309

  4. U.S. National Library of Medicine. Nabilone.

By Trisha Torrey
 Trisha Torrey is a patient empowerment and advocacy consultant. She has written several books about patient advocacy and how to best navigate the healthcare system.