This study aims to see if cannabidiol (CBD), a compound found in cannabis, can help reduce cravings and anxiety in people with opioid use disorder (OUD). Participants will be given either 200mg or 400mg of CBD twice a day or a placebo (a pill with no active drug) to compare effects. The study uses a method called a double-blind, randomized controlled trial, which means neither the participants nor the researchers know who gets the CBD or placebo until the study ends. Participants must be between 18-65 years old, understand and sign a consent form, and currently be on a methadone or buprenorphine treatment for at least 14 days. They must not have severe psychiatric conditions or other substance use disorders that could interfere with the study.

• The study lasts for a certain period, with regular check-ins and assessments.
• Participants may experience side effects or no effect from CBD.
• Compensation may be provided for participation and travel costs.