The goal of the study is to learn if Epidiolex (cannabidiol) works as a additional pain medication in patients who have had orthopedic shoulder surgery. It is also to learn about safe dosages and identify any side effects after surgery.

Researchers will compare Epidiolex to a placebo solution to see if Epidiolex lowers pain after shoulder surgery.

Participants will:

• track their pain and what medications they use every day in a provided pain diary. A researchers will call every seven days to check on the participant and diary.
• Complete two short surveys. Once before surgery and once after.
• Have bloodwork tested after surgery

Subjects will be randomized according to their surgery type. They will receive either the Epidiolex cannabidiol in addition to their standard of care pain regimen or a placebo in addition to their standard of care pain regimen. They will be asked to track a pain diary for 2 weeks postoperatively.

A member of the research team will conduct a follow-up telephone call on day 7 to assess subjects' drug compliance. Subjects will also be contacted for a safety monitoring call at day 7 and 1 week after completion of treatment in which they will disclose type, severity, onset, and duration of any adverse events. In addition, they will complete a suicidal assessment10 See attached safety screening document. After the 2 weeks, subjects will return the pain diary and vial of CBD/placebo at their postoperative appointment.

Subjects will also be asked to complete validated questionnaires via Houston Methodist's Redcap system once before surgery and again at 14 days postop. The surveys are with regards to sleep, activity, and pain and should take no more than 15 minutes to complete.

At their standard of care postoperative visit (11-17 days following surgery), another liver panel will be taken and their final safety monitoring screening will be conducted.

Inclusion Criteria:

• Above the age of 18 years old
• Undergoing a rotator cuff repair surgery
• Receiving standard anesthesia during surgery
• If a subject is of reproductive potential, they must be on effective contraception one month prior, during treatment, and one month following treatment.

Exclusion Criteria:

• Under the age of 18 years old
• History of revision shoulder arthroplasty
• History of liver disease or impairment
• Are currently taking valproate or clobazam
• Are currently taking a moderate/strong CYP3A4 or CYP2C19 inhibitor
• Are currently taking a strong CYP3A4 or CYP2C19 inducer
• Are currently taking narcotics
• History of substance/alcohol abuse
• Those currently or previously under the care of a pain management specialist
• History of marijuana/cannabidiol (not including topical) regular use within the past 6 months
• Allergy related to cannabidiol
• Allergy related to sesame seeds
• Pregnancy (As part of standard of care, all female participants will be administered a urine pregnancy test prior to surgery. A negative test result is required to participate in the study.)
• If you are taking any medications with known risks for suicidal behavior and ideation
• If you have a diagnosed psychiatric disorder
• If you are untreated for a diagnosed sleeping disorder
• If you are actively breastfeeding
• Patients currently taking central nervous system (CNS) depressants
• Patients currently taking other drugs with known hepatotoxicity
• Vulnerable populations.

Patients taking concomitant medications which are substrate of uridine 5'-diphospho-glucuronosyltransferase 1-9 (UGT1A9), uridine diphosphate-glucuronosyltransferase 2B7 (UGT2B7), CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, and P-gp will be monitored for potential adverse events based on the Epidiolex® label for the concomitant medication being used.