Despite marijuana’s federal classification as a Schedule I drug with no medical benefits, a new study confirms that marijuana has pain-relieving properties and could be used as a treatment for chronic pain. 

Nevertheless, doctors continue to hesitate in prescribing marijuana for pain relief where it is legal, due to a limited understanding of how the drug works—since research is hampered by its federally illegal status. 

While the effects on pain that anti-inflammatory medicines and opioids have are a bit better understood, more research is needed to understand how marijuana can decrease pain, researchers told Business Insider's Kevin Loria—who noted that although doctors aren’t quite sure how acetaminophen (Tylenol) works, they are more cautious about recommending cannabis without fully understanding its mechanisms. 

"Usually when you make decisions about which drug you are going to take for pain, you make that decision based on the type of pain you have and the relative risks for side effects," said Ryan Vandrey, an associate professor of psychiatry who researches marijuana at Johns Hopkins Medicine.

This is difficult because of the lack of information surrounding cannabis. For example, researchers aren’t sure what level of pain relief marijuana can provide—whether it is similar to taking Tylenol or Vicodin, for example. However, research into this area is hindered by federal law and marijuana’s continued classification as a substance with no acceptable medical benefits. 

Another issue that keeps providers from recommending marijuana for pain is the lack of "information about which types of products to choose, what doses to use, and how cannabis compares to other medications,” Vandrey said. 

The way that cannabis is ingested (whether it is eaten, smoked or used as an oil) can also affect its therapeutic benefits in a way that doctors and researchers do not yet understand. 

Some in the medical community feel that conducting more research is imperative, and soon. There are potential benefits to using marijuana for pain relief. Studies have shown that states with medical marijuana have lower rates of opioid overdose deaths than states without medical cannabis. 

“Overall, we find strong, consistent evidence that medical marijuana dispensaries lead to reductions in opioid-related mortality,” researchers of one study concluded.