Brief summary

This clinical trial is being done to better understand how daily treatment with Tetrahydrocannabinol (THC), Cannabidiol (CBD), or the combination of CBD plus THC affects knee osteoarthritis pain and other related symptoms. Consented participants will have a screening period and visit (up to 30 days to treatment start). If participants pass the screening phase, they will be randomly assigned to take one of the investigational study drugs. For this study, participants will not know when or if they are taking CBD, THC, THC plus CBD, and when or if taking placebo. Clinical pain will be assessed at multiple times throughout the study, and eligibility will be re-assessed at two weeks into the treatment period. It is possible that subjects will not be able to participate in the study after 14 days of of treatment. The treatment period will take approximately 16 weeks and then a follow-up period for approximately 2 weeks. In addition to treatment, participants will have clinical assessments, blood draws, questionnaires, daily pain diaries, sensory testing, as well as have functional connectivity magnetic resonance imaging (fcMRI).