Late last year, The U.S. Drug Enforcement Administration announced it was easing requirements for FDA-approved clinical trials of cannabis.

A group representing Pennsylvania physicians said now, the FDA needs to re-classify the substance.

“It’s almost impossible to do research on marijuana, because the DEA has it as what’s called ‘Schedule I,’ and substances which are listed under ‘Schedule I’ are deemed to be inappropriate for medical use and are therefore are very difficult, if not impossible, to do good, high-quality studies on like we would with other medications,” said Scott Shapiro, president of the Pennsylvania Medical Society.

Shapiro has sent a letter to the U.S. Food and Drug Administration, which approves drugs for medical use in the U.S., asking for marijuana to be rescheduled.

Last fall, the state’s medical society announced it would not endorse legalization laws for medical marijuana, because of a lack of studies on its effect on people. Shapiro said physicians aren’t opposed to the substance or using it, but need to better understand how and why it would be used. He said even in states that have legalized the substance for medical or recreational use, access is still limited because few doctors prescribe it.

“They [patients] trust that if we’re willing to prescribe a medicine, if we understand what we can reasonably expect their experience to be with the medicine,” said Shapiro. “And that’s the problem you have with marijuana, and that’s why physicians in other states just don’t write it (a prescription).”

A report from the Colorado Department of Public Health and Environment found that in November of 2015, 204 different physicians recommended medical marijuana for patients. That’s about 1.5 percent of Colorado’s physicians.

The FDA has not responded to Shapiro’s letter at this point, but he pointed to the DEA’s loosening of restrictions as a step forward.

“What that means exactly, with respect to the typical pipeline of changing something from ‘Schedule I,’ to ‘Schedule II’ is unclear. We’re cautiously optimistic that it has the same net effect, in that it will now, hopefully, allow researchers access to cannabis to be able to do some of these studies,” Shapiro said.

Senate Bill 3 is still in consideration in Harrisburg. It was passed by the Senate last year and was went to the House Health Committee, then to the Rules Committee.

The Pennsylvania Medical Society represents about 20,000 physicians and medical students in the state.