Medical marijuana has been found to be one of the safest methods of treating pain.  When people take THC or CBD (cannabidiol, the second most abundant compound in cannabis) for the relief of pain the endocannabinoid receptors can actually stop or seriously limit the pain impulses coming up to the brain from injured or swollen muscles, joints, nerves and skin or intestinal tissue. In addition, CBD works directly in those tissues to decrease or eliminate the inflammation that is such an integral part of the pain cycle. This is another difference with opioids as they have no anti-inflammatory pr