Tilray Inc. has received approval from the Drug Enforcement Administration to import cannabis into the U.S. for medical research, the first Canadian company to do so.

Tilray will work with the University of California San Diego’s Center for Medicinal Cannabis Research on a clinical trial to test whether the drug can effectively treat essential tremor, a common neurological disorder that causes uncontrollable shaking and affects more than 4 percent of people over age 65.

“I think it’s really exciting that we’re targeting this indication that no one else has thought of targeting,” said Catherine Jacobson, director of clinical research at Nanaimo, British Columbia-based Tilray. “It’s showing that these cannabinoids may be effective at treating a number of diseases that people hadn’t thought of before.”

Dr. Fatta Nahab, a neurologist at UC San Diego and the principal investigator for the study, said his first exposure to the idea of using cannabis to treat the disorder came a few years ago when a young male patient who he’d been tracking suddenly showed an improvement in his tremors.

“In talking to him further, he indicated he’d smoked some marijuana the night before, which led me to wonder whether this could be a feasible therapy,” Nahab said in an interview. A second elderly female patient also showed an improvement after trying cannabidiol, or CBD, a compound in cannabis that doesn’t have the same “high” effect as the THC compound.

The issue for medical researchers and doctors is that they don’t know what formulation or dosage works best when patients self-medicate using medical marijuana. Meanwhile, other patients who’ve tried cannabis and didn’t notice an improvement may have used an ineffective product or dosage.

“Patients are put in the uncomfortable position of having to go to a dispensary without any understanding of how cannabis works and just pick a product and hope that they get the dose right, hope that they get the product right,” Jacobson said.

The clinical trial will test an oral capsule with a 20-to-1 ratio of CBD to THC on 16 patients who have been diagnosed with essential tremor. Currently, the disorder is treated using drugs originally developed for high blood pressure or seizures.

Tilray is conducting four other clinical trials on the benefits of medical cannabis to treat post-traumatic stress disorder, chemotherapy-induced nausea, the side effects of glioblastoma—an aggressive type of brain cancer—and Dravet syndrome, a rare form of pediatric epilepsy.

The company’s stock price has soared since its trading debut in July, gaining over 600 percent to Monday’s close and surpassing a market value of $11 billion. Shares added another 9 percent in pre-market trading in New York on Tuesday.