Many people wonder if cannabis can help with long-term, hard-to-treat pain. The answer isn’t simple: research is ongoing, with both hopeful results and important gaps in what we know. People who live with chronic pain often hope cannabis can provide relief, but science hasn’t reached a final answer. In this article, we break down what we know so far about how cannabis might help with chronic pain, how it works in the body, results from research, what patients say, and how laws and regulations affect its use.
Chronic pain affects millions of people around the world. Standard treatments, including strong painkillers like opioids, do not always work and can come with risky side effects. This has led to growing interest in cannabinoids, the active chemicals in the cannabis plant (Cannabis sativa). These substances might help manage pain and inflammation by working with the body’s endocannabinoid system, a network that helps control pain and other functions. Let’s explore what science and patients have found about using cannabis for pain, along with its challenges.
Key Points About Cannabis and Chronic Pain
What is chronic pain?
Chronic pain is pain that lasts longer than normal healing-usually more than 3 to 6 months. Unlike short-term pain, which stops when your body heals from injury or illness, chronic pain can keep going for no clear reason. It often starts with conditions like arthritis, cancer, or fibromyalgia, but can also follow injury, surgery, or happen without a known cause.
- Affects about 1 in 5 people globally
- Leads to problems with daily activities, movement, sleep, and can harm mood and job or family life
- Is linked to stress, depression, and anxiety, making treatment harder
Medical vs. Recreational Cannabis
- Medical Cannabis: Prescribed by a doctor for health reasons, like pain relief.
- Recreational Cannabis: Used for enjoyment or to get “high,” often without medical supervision.
In places where both are legal (like Canada), these uses are kept separate. Patients using cannabis for their health usually prefer oils or capsules over smoking, aiming for more predictable effects and less association with non-medical use. Unfortunately, some people use cannabis on their own for pain, sometimes without a doctor’s advice.
Major Cannabinoids Used for Pain Relief
The Cannabis sativa plant has over 125 cannabinoids and many other chemicals. The two best-known for pain are:
- THC (delta-9-tetrahydrocannabinol): The main ingredient that causes a “high.” It helps with pain, sleep, and appetite, but can also cause anxiety, confusion, and other mental effects.
- CBD (cannabidiol): Does not cause a “high.” Used for its anti-inflammatory and calming effects. Many find it helpful for pain without mood changes or feeling “out of it.” Some prefer CBD to avoid the unwanted effects linked to THC.
Other cannabinoids like CBG and THCV are being studied for pain relief, and the mix of plant chemicals (called the “entourage effect”) might work better together than single ingredients alone.
How Cannabis Works for Pain
The Endocannabinoid System (ECS)
This is a part of the body that helps manage pain, mood, appetite, sleep, and more. It was discovered in the 1990s and is now recognized as key for keeping the body balanced.
The ECS has:
- Endocannabinoids: Natural chemicals (like anandamide) made by your body;
- Receptors (CB1 & CB2): Found in the brain, spinal cord, and other areas.
When pain or injury occurs, the body makes endocannabinoids to control pain signals. In people with chronic pain, this system may stop working properly, meaning cannabis could help by supporting these signals.
How THC and CBD Act in the Body
THC:
- Attaches to both CB1 and CB2 receptors.
- Blocks pain signals in parts of the brain and nervous system.
- Can also cause mood changes, memory problems, and sometimes anxiety.
CBD:
- Works differently-it mostly doesn’t bind to the same receptors.
- May reduce pain and inflammation by calming certain brain and immune pathways.
- Doesn’t cause a “high” and is less likely to cause mood problems.
Newer cannabinoids are being tested, and the ways these substances work together aren’t fully clear yet. Some may have benefits without causing a “high.”
THC:CBD Ratios and the “Entourage Effect”
Many believe that using THC and CBD together can help ease pain while balancing side effects. For example, a 1:1 or 1:4 ratio (more CBD than THC) may offer relief with less risk of feeling high or anxious. Studies of products like Sativex (a spray with THC and CBD) show pain relief with fewer mental side effects than THC alone. The best balance is still being worked out.
Ways to Use Cannabis for Pain
Common Methods
| Method | Onset Time | Duration | Notes |
|---|---|---|---|
| Inhaled (smoking or vaping) | 5-10 minutes | 2-4 hours | Fastest relief; more intense side effects |
| Oral (edibles, oils, capsules) | 30 minutes-2 hours | 6-8 hours | Slower, longer-lasting relief; hard to predict effect timing |
| Sublingual (under tongue sprays/tinctures) | 15-45 minutes | 4-6 hours | Faster than edibles; easier dosing |
| Topical (creams, balms, patches) | Varies | Local only | For specific areas; doesn’t affect mind |
Dosing Challenges
Unlike standard drugs, cannabis products have very different strengths, chemicals, and dosing instructions. One “dose” can mean very different things depending on the product or how it’s used. Most people are told to “start low and go slow,” increasing their dose gradually with a doctor’s help.
Bioavailability (How Much Gets Into Your Body)
- Smoking/Vaping: About 10-35% of THC or CBD reaches the bloodstream quickly.
- Oral: Only about 4-12% reaches the bloodstream (after digestion and liver filtering).
- Bioavailability varies by method, your metabolism, what you eat, and product type.
What the Research Shows
Main Studies and Reviews
- Some studies show cannabis (especially combined THC and CBD) can provide small to moderate pain relief versus placebo.
- Evidence is mixed, especially for different pain types and products. Some patients have a clear benefit; others do not.
- For some groups, cannabis helped lower pain if standard painkillers were failing (for example, people with cancer pain who did not respond to opioids).
| Pain Type | Effectiveness | Notes |
|---|---|---|
| Neuropathic pain (nerve) | Moderate benefit in some trials | Best evidence for this type |
| Musculoskeletal pain | Mixed results | Not clearly better than placebo |
| Cancer-related pain | Some clear benefit, especially combined with standard treatments | Sativex helped some patients reduce opiates |
| Fibromyalgia or MS pain | Some trials support use | More research needed |
Cannabis vs. Opioids
Some patients and researchers hope cannabis could reduce the need for opioids (which carry addiction and overdose risks). Surveys show patients often feel cannabis is safer, and in some places, fewer opioid prescriptions are written where cannabis is easily available. However, research so far has mixed results. Some studies see less opioid use, others do not. While cannabis does not suppress breathing (a main cause of opioid overdose death), it has its own risks, and we need more clear, direct comparisons.
What’s Missing in the Research
- Studies use different types, doses, and forms of cannabis, making comparisons hard.
- Many clinical trials are small or short-term; few look at long-term results.
- Laws make research hard, especially in countries like the U.S. where cannabis is strictly controlled.
- We don’t know the long-term side effects or risks for most patients.
- People with different causes of pain may respond very differently to cannabis.
- The mental and mood-changing effects of THC can mix with pain relief, making outcomes harder to measure.
Patient Experiences: What Do People Say?
Why Patients Turn to Cannabis
- Standard medications (like opioids or antidepressants) don’t work, or side effects are too hard to handle.
- They see cannabis as more “natural” or less risky.
- They hope to feel better overall-not just pain, but sleep, mood, or ability to move.
- Increasing legality, social acceptance, and information sources make them more willing to try.
Reported Benefits
- Less pain and more relaxation
- Better mood and less anxiety
- Improved sleep
- Easier daily life (moving, doing chores, spending time with family)
- A feeling of having some control over their pain
It’s not all positive-some report side effects (like tiredness or anxiety), and a few are nervous about using cannabis even as medicine.
Barriers: Costs, Stigma, and Laws
- Cost: Medical cannabis usually isn’t covered by insurance, and can be expensive. Some buy from illegal sources to save money, which may not be safe.
- Stigma: Some people worry about being judged for using cannabis, even for medical reasons.
- Legal Issues: Laws are different everywhere. Some places make it very hard to get a prescription, or only certain forms are legal. Some people travel and can’t take medical cannabis with them. In many areas, pharmacists can’t provide or explain cannabis products.
What Surveys and Testimonials Show
- Many patients are happy with cannabis, saying it helps more than hurts.
- Younger people and those with more pain are more likely to use it.
- Most prefer non-smoking forms for medical use and want to separate their use from recreational users.
- Patients want clear, reliable advice on how to use cannabis, but often can’t get it from doctors or pharmacists.
- Healthcare workers say they need more education and research to help their patients safely.
Risks and Side Effects
Short-term Side Effects
| Type | Example Side Effects |
|---|---|
| Cognitive | Memory troubles, difficulty focusing, confusion |
| Psychological | Anxiety, paranoia, mood swings, sometimes temporary psychotic symptoms |
| Physical | Drowsiness, dizziness, dry mouth, headache, stomach upset, increased appetite, cough (if smoked), heart rhythm changes |
These effects are usually temporary, but sometimes strong enough to make people stop using cannabis.
Long-term concerns
- Dependence/Addiction: Some people can become dependent (<10%), especially with daily or heavy use.
- Tolerance: The body can get used to cannabis, needing bigger doses for the same pain relief.
- Mental Health: Long-term use (especially started younger or with high-THC products) may increase risk of depression, anxiety, or even psychosis in vulnerable people.
- Heart Risks: May affect heart rate and blood pressure, with rare links to heart attacks or stroke.
- Gastrointestinal: Heavy, long-term use may cause repeated nausea and vomiting (Cannabinoid Hyperemesis Syndrome).
- Other: Could affect organs, reproductive health, or lungs (mainly with smoking).
Drug Interactions
THC and CBD are broken down by liver enzymes that also handle many medicines. This means combining cannabis with other drugs (e.g., blood thinners, epilepsy drugs, immune suppressants, statins, opioids, sedatives) can lead to higher or lower drug effects. It’s especially risky for older people or those on many medicines.
People with certain medical conditions (mental illness, heart disease, pregnancy, breastfeeding) should be careful or avoid using cannabis for pain.
What Healthcare Providers and Patients Need to Know
Who is a Candidate for Medical Cannabis?
- Assess the patient’s pain: Type, severity, and what’s been tried so far.
- Take a full health history: Focus on mental health, heart, and liver conditions.
- Review other medications for possible dangerous interactions.
- Discuss expectations-make sure patients know the limits of what cannabis can do and risks involved.
Shared decision-making is key. Starting with low doses and slowly increasing helps reduce unwanted effects or dependence.
How to Monitor Cannabis Treatment
- Regularly review pain, function, mood, and life quality
- Ask about side effects
- Watch for drug interactions or need to change other medications
- Check for signs of dependency or tolerance
- Include cannabis as one part of a larger pain plan (with physical therapy, counseling, etc.)
- Keep detailed records of what was used and the outcomes
Education Gaps
- Many doctors and pharmacists feel they don’t know enough about cannabis.
- Patients often get information from the internet or cannabis shops, not health professionals.
- More training and simple, trustworthy educational materials are needed-for both patients and healthcare teams.
Laws, Regulations, and Access
How Laws Differ by Country
| Region | Status | Notes |
|---|---|---|
| Canada | Legal (medical & recreational) | Doctors can authorize, but pharmacists don’t dispense |
| USA | Mixed | Medical/recreational legal in some states, but federally illegal (as of June 2024, may move to Schedule III) |
| Europe | Country-specific | Some (e.g., Germany) allow medical, others restrict or ban |
| Finland | Very limited | Legal on paper, but very hard to get a prescription |
Getting a Prescription and Who Qualifies
- Usually requires a diagnosis of chronic pain not managed by other treatments
- Specific rules for types of products (e.g. flower, oils, or synthetic cannabinoids)
- Can involve extra steps: special doctors, specialized clinics or suppliers, and follow-up visits
Some areas allow medical cannabis only in certain forms, often making pharmacists less involved. This can create confusion or gaps in patient support.
Insurance and Cost Issues
- Most insurance does not pay for medical cannabis. Patients pay out-of-pocket.
- High prices for legal cannabis vs. street prices push some patients to unregulated sources.
- Cost is often the main reason people stop their cannabis treatment.
If more research proves cannabis is effective and safe, insurance may be more likely to cover it in the future.
What’s Next?
New Cannabinoids and Products
Researchers are looking at lesser-known cannabinoids like CBG, CBC, and THCV for pain relief-some may help without causing a high. New product forms (like patches, sprays, or precisely balanced oil blends) aim for steady, targeted effects with fewer side effects.
Future Research Needs
- Bigger, longer studies to prove safety and effectiveness
- Standard products and exact dosing instructions
- More data on long-term side effects and drug interactions
- Direct comparisons with opioids and standard painkillers
- Better understanding of how different cannabinoids affect pain
- Focus on what matters to patients-like function, mental health, and sleep, not just pain scores
- Research for specific pain types to help doctors match the right product to the right patient
The Changing Place of Cannabis in Pain Care
Cannabis is shifting from a controversial or last-resort option to a possible standard part of pain care, especially if used alongside other treatments. It may never be a cure-all, but for some, it helps manage pain when other treatments fail. Laws are changing, and healthcare providers will need education, guidelines, and research to keep up. Over time, cannabis may take its place as one piece of a large pain-management puzzle-used safely, with good information, and tailored to the needs of each patient.