Cannabis for Pain Relief
Cannabis contains over 100 compounds called cannabinoids. The two main ones are THC and CBD. THC causes a high. CBD does not. Both interact with the body's endocannabinoid system, which helps regulate pain signals.
Research shows cannabis may reduce chronic pain in some people. The evidence is strongest for neuropathic pain (nerve damage) and multiple sclerosis-related pain. Evidence is weaker for acute pain, like a headache or a sprained ankle.
The FDA has not approved cannabis or CBD for pain. The agency has approved three cannabis-related drugs: Epidiolex (CBD) for seizures, Marinol (dronabinol) and Cesamet (nabilone) for chemotherapy-induced nausea. No approved product lists pain as an indication.
Forms of Cannabis
- Smoked flower: effects start in minutes, last 1-3 hours.
- Vaporized oil: similar timing, fewer toxins than smoke.
- Edibles: effects start in 30-90 minutes, last 4-8 hours.
- Tinctures: drops under the tongue, effects start in 15-45 minutes.
- Topicals: creams and salves for local pain. Little THC enters the blood.
CBD vs. THC for Pain
CBD from hemp has less than 0.3% THC. It is legal at the federal level under the 2018 Farm Bill. CBD may help with arthritis pain and anxiety-related pain. Studies are small. Doses in studies range from 10 mg to 400 mg per day.
Cannabis for Treating Pain: A Comprehensive Guide
THC has more evidence for pain relief. A 2020 review in the journal Pain found that THC reduces chronic pain by about 30% in some patients. That is similar to some prescription drugs. But THC can cause side effects: dizziness, dry mouth, drowsiness, and memory problems.
What the Research Says
- Chronic pain: Moderate evidence. A 2018 review by the National Academies found cannabis effective for chronic pain in adults.
- Neuropathic pain: Moderate evidence. Studies show a 30% reduction in pain scores.
- Cancer pain: Low evidence. Some patients report relief, but studies are mixed.
- Fibromyalgia: Low evidence. A small 2020 study found no significant difference from placebo.
- Migraine: Low evidence. A 2019 study found cannabis reduced migraine frequency by half in some users.
Risks and Side Effects
Common side effects include dizziness, dry mouth, red eyes, and fatigue. THC can impair driving and concentration. Long-term use may lead to dependence in about 9% of adults. CBD can cause diarrhea, changes in appetite, and liver injury at high doses.
Cannabis interacts with blood thinners, antidepressants, and seizure drugs. Talk to a doctor before use if you take other medications.
Lab Testing and Product Labels
CBD products sold online are not all tested. Look for a certificate of analysis (COA) from a third-party lab. The COA should list cannabinoid content and test for pesticides, heavy metals, and solvents. A 2017 study in JAMA found that 70% of CBD products online had inaccurate labels.
In the US, CBD with less than 0.3% THC is legal at the federal level. But some states have stricter rules. Check your state law.
Dosing
No standard dose exists. Start low, such as 5 mg of CBD or 2.5 mg of THC. Wait 2 hours before taking more. Keep a log of effects. The right dose depends on your weight, condition, and product.
Talk to a Doctor
Tell your doctor about all cannabis or CBD use. They can check for interactions. They can also advise on other pain treatments.