There are many reasons to be excited about the medicinal benefits of cannabis. Research is progressing quickly in multiple parts of the world; U.S. research is beginning to pick up steam as more and more states legalize cannabis for medicinal or recreational use, which makes research easier to conduct.

Based on promising, preliminary research, cannabis advocates can claim that cannabis may be effective in treating:

And this list is not even comprehensive! Furthermore, there are likely many more studies coming that will add new treatments to this list or strengthen existing findings.

In addition to these results, an even stronger evidence-based claim can be made for the use of cannabis to treat at least three negative health conditions:

  • Chronic pain

  • Chemotherapy-induced nausea and vomiting

  • Multiple Sclerosis

This is supported by a 2017 report by the National Academies of Sciences, Engineering, and Medicine that analyzed over 10,000 scientific studies on cannabis.

That said, let’s get into the nuts and bolts of what make these evidence-based claims about medicinal cannabis so strong.

Chronic Pain 

About Chronic Pain:

The types of pain that people reported in these studies included general pain, pain symptoms from cancer, and neuropathic pain, which affects the somatosensory nervous system.

What’s the evidence that cannabis helps with pain?

  • A 2016 review of medical research studies from as early as 1948, which included 28 randomized clinical trials, concluded “Use of marijuana for chronic pain . . . is supported by high-quality evidence.” 

  • Another review in 2018 of nine studies found that cannabis was effective in treating pain compared to a placebo (though two of the studies found that cannabis was no more effective than a placebo). 

  • Also, a 2018 study of over 900 Israeli cannabis users over 65 years old found that “93.7% reported improvement in their condition . . . the number of reported falls was significantly reduced . . . [and] cannabis decreased the use of prescription medicines, including opioids.” Notably, 75% of these individuals had never used cannabis before!

What are the limitations of this research?

As with all pain medications, cannabis doesn’t work for everyone, all of the time, to treat pain. A 2015 meta-analysis (an analysis of multiple studies) of five randomized, controlled trials found that “inhaled cannabis results in short term reductions in chronic neuropathic pain for one in every five to six patients treated.” However, this inconsistent effect is not unique to cannabis; people often have different reactions to pain medications. This study also concluded that the effect of cannabis on pain was only short-term, not long-term.

Also, some of the pain relief that patients experience from cannabis could be attributed to a placebo effect; as noted above, some studies find that cannabis is no more effective in treating pain than a placebo.


About vomiting/nausea:

Many patients suffer from nausea and vomiting due to their chemotherapy treatments.

What’s the evidence that cannabis helps with vomiting/nausea?

Unlike many other areas of cannabis research, the use of cannabinoid medications to treat chemotherapy-induced nausea and vomiting was approved back in 1985. Decades of research have clearly demonstrated that these cannabinoid medications are more effective than a placebo and at least as effective as “treatment as usual” medications.

  • A 2010 study found that, compared to a placebo group, cannabis helped prevent vomiting and nausea in cancer patients who were also taking a standard anti-nausea medication to cope with their chemotherapy. 

  • A 2015 meta-analysis  reached a similar conclusion.

What are the limitations of this research?

Rather than testing the effect of consuming the cannabis plant, studies have tested synthetic cannabinoid medications (not to be confused with synthetic cannabis, aka K2 or Spice). Although it is plausible that consuming the cannabis plant could work just as well as synthetic cannabinoid medications, the evidence currently does not support this claim. 

Multiple Sclerosis (MS)

About MS:

Defined as “an unpredictable, often disabling disease of the central nervous system that disrupts the flow of information within the brain, and between the brain and body.”

What’s the evidence that cannabis helps with MS?

Meta-analyses conducted in 2014 and 2015 both found that cannabinoid medication was effective in treating spasticity (involuntary muscle movement) in patients with MS.

What are the limitations of this research?

Similarly to what we said about vomiting/nausea research, the evidence for treatment of MS is generally based on synthetic cannabinoid medication, not the cannabis plant. 

As cannabis research studies continue to multiply exponentially, cannabis advocates will be able to more and more confidently claim the medicinal benefits of cannabis. Until then, we can be thankful that there is already so much research showing the benefit of cannabis for people suffering from serious negative health conditions.