There are now controlled trials in this area, but they answer different questions.

• Instead of opioids for chronic back pain: Limited. In a 2025 trial, 384 adults with chronic low back pain were randomly assigned to a standardized THC extract (VER-01) or to opioids for 6 months. Pain fell slightly more with the cannabis extract (2.5 versus 2.2 points out of 10). Patients on the extract were four times less likely to develop constipation. Patients and doctors knew which treatment they were getting, and it is one specific product.
• Lowering the dose for people already on opioids: Limited, but the New York evidence is growing. In a 2026 study of 204 Bronx adults on opioids for chronic pain, each month with a 30-day supply of medical cannabis was linked to 3.5 fewer morphine milligram equivalents (MME) per day, with dispensing tracked in the state Prescription Monitoring Program (Slawek 2026, JAMA Internal Medicine). An earlier study of 8,165 New Yorkers on long-term opioids found daily doses fell 47–51% among those using cannabis for more than 30 days, versus 4–14% among others (Nguyen 2023, JAMA Network Open). Both were observational, so they show an association, not proof. Pooled observational studies elsewhere report that 85% of patients cut their dose and 39% stopped; controlled trials have not confirmed this, partly because most told patients to keep their opioid dose unchanged.
• Cancer pain on top of opioids: Not established. Trials found no reduction in opioid needs.
• Craving in opioid use disorder: Limited. In a 2019 trial of 42 people in recovery from heroin use, oral CBD reduced cue-triggered craving and anxiety. CBD is not a substitute for buprenorphine or methadone.

Compared with standard treatment: A 2024 review of 90 trials found cannabis medicines and opioids gave similar small improvements in chronic non-cancer pain, with fewer stops for side effects on cannabis.

Good to know: Never lower an opioid dose on your own; stopping suddenly can cause withdrawal and raises overdose risk if you restart. Neither New York study used a set taper plan; opioid changes were left to each patient’s own prescriber. The best-designed approach under study, a Massachusetts General Hospital trial, lowers the dose by about 10% of the starting dose once a month, only when the patient agrees, with weekly support sessions, withdrawal checks, and naloxone on hand (trial protocol). Ask your prescriber about a gradual plan like this. Cannabis and opioids together can increase drowsiness.

What to ask for: For pain, see Chronic pain. A THC-dominant oral extract is the product that was compared with opioids. CBD for craving has been studied only at research doses and only alongside addiction treatment.