In one of the firs real-world studies to look at the medicinal use of smoked marijuana, researchers found that people with chronic pain who weren’t seeing enough relief from standard medications could be helped by smoking small amounts of marijuana. In addition, patients could fall asleep more easily and sleep more soundly, CNN reports. While other studies have looked at extracts of THC, the cannabis plant’s active ingredient, “this is the first time anyone has done a trial of smoked cannabis on an outpatient basis,” lead researcher Mark Ware, the director of clinical research at McGill University’s Alan Edwards Centre for Research on Pain, said. In the study, 21 adults with nervous-system pain due to surgery, accidents or other trauma—fourteen of whom were on short-term disability or permanently disabled—smoked four different strengths of marijuana over 56 days. All of them had tried the drug before, but none were habitual current users. The highest dose of THC showed the best results, while the two medium-strength doses produced no measurable relief. The effects lasted 90 minutes to two hours.