**Study Overview:** This study is looking at how using medical cannabis (MC) might change the way people with long-term pain use opioid painkillers. Participants will be split into two groups: one using MC and one not using any cannabis. Over three months, participants will fill out surveys about their pain, sleep, and mental health. **Key Points:** - **Duration & Assessments**: The study lasts 3 months. Participants will complete daily and monthly surveys about their pain and medication use. - **Participation Requirements**: Participants must be over 18, have chronic pain, and use prescription opioids. Some will need to be certified to use MC in Pennsylvania. - **Cannabis Products**: Those in the MC group will try different types of MC products monthly, each with varying amounts of THC (a chemical that makes you feel "high") and CBD (a chemical that helps with pain and relaxation). Participants will also report any side effects and changes in their quality of life. This study will help us understand if MC can help reduce opioid use and improve life quality.