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Can Marijuana and CBD Help With Ulcerative Colitis Symptoms?

Medically Reviewed by Neha Pathak, MD on August 11, 2026

If medications you take to treat your ulcerative colitis (UC) symptoms aren’t working, you may wonder if there are other options. In recent years, there has been a lot of debate about whether alternative treatments, such as marijuana or cannabidiol (CBD), can help ease UC symptoms. But do they? And could they be right for you? Learn what the science says about how they might or might not work for UC.

It’s useful to understand the difference between marijuana and CBD. Marijuana, also called cannabis or weed, comes from a plant called Cannabis sativa. People sometimes use it for recreational or medicinal purposes. It contains two main active ingredients: delta-9 tetrahydrocannabinol (THC) and cannabidiol (CBD). It’s the THC in marijuana that gives you a high.

CBD is a chemical found in cannabis (marijuana). It’s derived in two ways: from hemp (a plant closely related to marijuana) or made in a lab. It produces a calming effect but doesn’t make you high, and it’s not addictive.

Does either help with UC? Some researchers and doctors are exploring the possibility that cannabis, in one form or another, helps people with inflammatory bowel disorders, including UC.

What does science say?

Research is mixed. 

“There is a percentage of patients who use cannabis and feel better,” says Jami Kinnucan, MD, a gastroenterologist at the University of Michigan. “Their symptoms — most commonly abdominal pain or body pain, diarrhea, appetite, and nausea — improve.” But in other cases, results are less promising. In a study of patients with UC in Canada, patients who used cannabis to treat their symptoms reported worse abdominal pain and gas, reduced appetite, and worse quality of life than those who didn’t use it.

Though research is limited, small studies have shown that medicinal marijuana may ease several UC symptoms, such as pain, nausea, and reduced appetite.

Can cannabis improve inflammation in UC?

Inflammation in the digestive tract is tied to UC symptoms, including diarrhea, pain, cramping, bleeding, and fatigue. A primary aim of treatment is to stop the inflammation.

There’s some evidence in mice suggesting that cannabis could help with inflammation. This has to do with certain receptors that respond to other cannabinoids our bodies make naturally. When the cannabinoids in CBD connect with those in our body, they cause a reaction in the gut that may ease common UC symptoms, such as nausea, vomiting, and pain. Cannabis may also slow the digestive tract. But it isn’t clear that smoking cannabis or taking it in a capsule fights the underlying inflammation in people with UC.

In one small clinical trial, people with UC who took CBD capsules containing a small amount of THC for 10 weeks were no more likely to go into remission than those taking a placebo. Smoking two marijuana cigarettes a day didn’t lower the signs of inflammation either.

“If you do blood work, imaging, or stool samples, patients’ numbers don’t change,” Kinnucan says. “While they may feel better, their inflammatory burden isn’t improving.”

The CBD study reported that the 10-week treatment improved quality of life. But the study’s participants also reported side effects, including dizziness, trouble paying attention, headache, nausea, and fatigue. Dizziness was the most common reason people in the CBD study dropped out. The marijuana study didn’t report on side effects or quality of life.

A recent review of the two clinical studies suggested that the effects of cannabis and CBD in people with UC remain uncertain. There’s no evidence that it can help put people with UC into remission.

But it’s too soon to say whether it sometimes helps in other ways and how safe it is.

Kinnucan says that cannabis might help some patients with UC and not others. For those with UC that’s controlled by medication, she says there’s no reason to think adding cannabis would help. It’s never a good idea to replace approved medicines with cannabis. There’s a risk that cannabis could mask symptoms and lead people to stop necessary treatments.

“At the end of the day, if the hope is to control inflammation, there is no data to support that,” Kinnucan says.

What’s most important for people with UC is to continue with treatments that doctors know work. If you continue to have symptoms, Kinnucan says a doctor should examine your disease to make sure the treatments you’re taking are sufficient. But if you or a loved one is taking medications as prescribed to control the UC, there’s a chance that cannabis might help with lingering symptoms such as pain or nausea. If you and your doctor decide you can try cannabis, Kinnucan suggests taking it orally over smoking it (because of the risks of smoking) and starting with the lowest THC levels.

Kinnucan says more doctors and patients should talk about cannabis, including how and why patients might be using it on their own. But for now, it’s difficult for doctors to know how to advise people with UC about how they might use cannabis safely. Studies of cannabis for inflammatory bowel diseases, including UC, are ongoing, so more data will become available.

Even if marijuana is legal in your state, you still want to be careful. Here are some things to keep in mind before you buy:

Buy it on the legal market. Cannabis sold on the legal market is tracked from the time it’s grown from seed until it’s sold. It’s checked for harmful chemicals, pesticides, and fungus.

Read the label. This lets you know what’s in the cannabis you’re buying.

Follow your doctor’s advice. People who work in cannabis dispensaries (budtenders) might seem to know which types work best for certain health conditions. But even though they mean well and might seem to be knowledgeable, they’re not doctors. If you have any questions about what cannabis you should buy for UC or how much you should take, ask your doctor.

Use the lowest effective dose for the shortest time possible. If you take too much cannabis or try a strain that’s too strong, it could cause a severe anxiety attack or other serious reactions, including cardiac conditions.

You can buy cannabis in several forms, including:

  • Those that can be inhaled (smoked)
  • Edibles
  • Tinctures
  • Skin patches (transdermal)

Talk to your doctor if you’re thinking about using cannabis to treat UC symptoms. They’ll tell you if it’s safe to use based on your condition. Avoid using cannabis if you:

  • Are pregnant or breastfeeding
  • Have heart disease
  • Have mental health disorders
  • Have a history of substance misuse
  • Take anti-seizure medications
  • Take blood thinners or herbal supplements

Most often, CBD is sold as an oil, but you can also buy it in many other forms, such as:

  • Tinctures
  • Capsules
  • Patches
  • Vapes
  • Topicals
  • Gummies

You can also purchase CBD-infused food, drinks, and beauty products online.

CBD isn’t regulated by the FDA — except for one product approved to treat epilepsy. 

With other CBD products, the biggest risk is that you don’t really know what you’re getting. CBD products you buy online may contain unknown or harmful ingredients not listed on the label. Or they may contain higher or lower doses of active ingredients listed on the label. Also, there are no federal guidelines about proper CBD dosage, so it’s not clear how much is safe to take.

If you plan to use CBD, talk to your doctor. They can help you decide if it is right for you and how much you should take based on your condition, overall health, and other factors. And if you buy products containing CBD online, make sure they have a certificate of analysis (COA), which shows that they were tested by an independent laboratory.

Potential side effects

CBD may cause side effects, such as dry mouth, diarrhea, reduced appetite, drowsiness, fatigue, and irritability. It can also cause liver damage. CBD can also interfere with several medications, including:

  • Blood thinners
  • Anti-seizure medications
  • Immunosuppressants
  • Over-the-counter (OTC) painkillers
  • Antihistamines
  • Psychiatric medications

If you take any of these medications, talk to your doctor before you try CBD. 

In addition to whether it works, doctors and patients also have legal issues to consider when it comes to cannabis. 

Marijuana isn’t approved by the FDA for medical use, but it’s legal in some states, depending on where you live and whether you use it for medicinal or recreational purposes. In some states, it’s legal to use marijuana for both medicinal and recreational purposes — as long as you meet the minimum age requirement. In other states, it’s legal to use marijuana only for medicinal purposes. For example, in Michigan, recreational marijuana is legal, but medical marijuana requires a confirmed diagnosis from two doctors. UC is on the list of qualifying conditions for medical marijuana in most states.

In some states, no form of cannabis is legal. The federal Drug Enforcement Administration (DEA) also recognizes marijuana, including medical marijuana, as a controlled substance.

“We have patients who live in one state and drive across state lines to obtain cannabis but then illegally bring it back in,” Kinnucan says. “You should refer to your state laws. Crossing a border can be a criminal activity.”

What about CBD?

It depends on your state. In 2018, Congress removed hemp from the federal Controlled Substances Act. This means that in most cases, CBD is legal if it’s produced from hemp and contains less than 0.3% THC.

But some states haven’t removed hemp from their controlled-substances lists.

There is no one “right” time to talk to your doctor about using cannabis to treat your UC. You may want to start the conversation if:

  • Traditional treatments aren’t working.
  • Symptoms are getting worse.
  • Pain and symptoms are affecting your quality of life.

Here are some tips to help you get the most out of your talk with your doctor:

Write down your questions and concerns. Tell your doctor about any new symptoms, medication side effects, or new issues you’ve noticed since your last visit. If medications aren’t working or you don’t like the way they make you feel, tell your doctor.

Do your research. Find out what studies say about using cannabis to treat UC symptoms. What are the side effects? How might it interact with other medications you’re taking? The more informed you are, the more confident you’ll feel when you talk to your doctor.

Know what’s legal and what’s not. Does your state allow cannabis for medical or recreational use? What does your employer, landlord, or homeowner’s association say about cannabis use? Thoroughly review legal documents, such as your employee handbook, lease agreements, or HOA bylaws, to avoid legal issues.

How to start the conversation

Be honest and direct. It’s always best to talk to your doctor before you start taking cannabis so that they can tell you about any possible interactions with other medications you might be taking. You could say something as simple as, “I did some research and learned that cannabis can reduce UC pain. I’d like to try it to see if it might help.”

If you’ve already started taking it, let your doctor know. You could say something like, “I started taking cannabis to treat my UC pain,” and tell your doctor about any symptoms or side effects.

Remember that your doctor is your partner in health care. The more they know about your health care needs and desires, the more they can help.

Why your doctor may disagree and what to do about it

Even if medical marijuana is legal in your state, your doctor may advise against using it to treat UC. There could be several reasons. One of the biggest reasons is that doctors aren’t sure that cannabis lowers inflammation caused by UC. While cannabis may relieve UC symptoms like pain and nausea, it doesn’t treat the disease.

Your doctor might also advise against cannabis use if you have other health conditions or take other medications that might interact with cannabis.

If your doctor disagrees, tell them you’d like to get a second opinion so you can make the most informed decision. Doctors often expect and encourage patients to request a second opinion.

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