Cannabidiol for Fibromyalgia (The CANNFIB Trial)

Inclusion Criteria: * Informed consent obtained * Clinical diagnosis of fibromyalgia according to the American College of Rheumatology (ACR) 1990 criteria * Average pain intensity ≥ 4 on a Numeric Rating Scale * No use of medical cannabis (THC/CBD) within the last six months * Proficiency in spoken Danish language and able to read and write in Danish Exclusion Criteria: * On-going participation in other medical trials for pain management of fibromyalgia * Diagnosis of Rheumatoid Arthritis or other inflammatory diseases * Diagnosis of other serious chronic diseases * Impaired liver and kidney function * Pregnancy or insufficient anti-conception therapy for fertile female participants * Planning pregnancy or insufficient anti-conception use in fertile female partners of male participants * Breast feeding * Surgery scheduled for the trial period or within 3 months prior to enrollment * History of or current diagnosis of cancer * History of or current epilepsy and seizures * History of or major depressive disorder * History of a suicide attempt or any suicidal behavior * A mental state that may impede compliance with the program * History of severe psychiatric disorders * History of or current cannabis abuse * History of or current drug abuse * History of or current alcohol abuse * Severe personality disorder * Current use of opioids, opioid antagonists (LDN) or similar strong analgesics * Allergic reactions to the active ingredients in cannabidiol