Cannabis and Kidney Disease–What You Need to Know

Cannabis, also known as marijuana, pot, or weed, has been used for medicine, rituals, and even making rope for thousands of years.

But today, more people are asking: Can it help with kidney disease? Is it safe? And what do we know about how it affects the kidneys?

Kidney specialist and researcher Dr. Joshua Rein breaks it down. 

• What Is Cannabis?
• Can Cannabis Help People with Kidney Disease?
• Are There Risks to Using Cannabis?
• Cannabis and Kidney Transplantation
• How to Use Cannabis More Safely
• What About CBD?
• Talk to Your Healthcare Team
• Have Questions? 

Listen to "Cannabis & Kidney Disease: Is it OK to be high?" on Spotify or Apple Podcasts. 

Cannabis is a plant with natural chemicals called cannabinoids that affect the body when consumed.

Two of the most well-known cannabinoids are:

• THC (tetrahydrocannabinol) gives people a “high” feeling.
• CBD (cannabidiol) doesn’t make people feel high but may help with pain, anxiety, and inflammation.

There are different types or strains of cannabis plants:

• Sativa may increase energy or give an uplifted feeling.
• Indica tends to be more calming and helps with sleep.
• Hybrids are a mix of both, with a variety of effects.

Cannabis also contains terpenes. Terpenes are natural oils that give cannabis strains their unique smell and effects.

For example:

• Limonene smells citrusy and may improve mood.
• Myrcene smells earthy and may help with sleep.
• Pinene smells like pine and may increase alertness.

Some people living with kidney disease use cannabis to help manage symptoms like:

• Pain
• Nausea or vomiting
• Loss of appetite
• Trouble sleeping
• Itchy skin (pruritus)
• Restless leg syndrome

Cannabis may be especially beneficial for people who can’t use traditional pain medications like:

• Opioids: Can cause constipation, confusion, and dependence.
• NSAIDs (non-steroidal anti-inflammatory drugs): May damage the kidneys.
• Acetaminophen: Safer for kidneys but may not help enough for chronic or severe pain.

“Cannabinoid-based treatments are currently used to treat other conditions,” said Dr. Rein. “There is an FDA-approved drug called dronabinol that uses synthetic THC to help patients with cancer or HIV improve their appetite and reduce nausea.”

There are possible downsides to using cannabis for kidney disease. Dr. Rein’s retrospective cohort study found that people who used cannabis had a faster decline in kidney function than those who didn’t.

Let’s break down what that means:

• Retrospective means researchers look at existing research rather than start a new experiment.
• Cohort refers to a group of people who were studied over time—in this case, some who used cannabis and some who didn’t.

“Normally, kidney function decreases one eGFR point a year,” Dr. Rein explained. “Our study found that people who consumed cannabis lost around 2 points per year.”

But this study had some limitations.

• Only a small number of people in the study used cannabis.
• Those who used cannabis often had other risk factors like smoking cigarettes or high blood pressure that could have affected kidney health, too.
• Today’s cannabis is much stronger than it was in the past. This makes it harder to compare older research to current cannabis products.

“We can’t say for certain how cannabis affects kidney function,” said Dr. Rein. “The study lacks the power to truly make any kind of definitive conclusion.”

More research is needed to determine if cannabis use on its own negatively affects the kidneys.

Want to help researchers learn how kidney disease affects daily life? Join NKF’s KidneyCARE Study to be part of research that could shape the future of kidney health. 

Cannabis use alone doesn’t usually disqualify someone from getting a kidney transplant.

“If cannabis use interferes with your medications or makes it harder to follow your care plan, you may get disqualified,” said Dr. Rein. “Every center is different, though. Be sure to check in with them before using cannabis.”

Cannabis (especially CBD products) can also interact with immunosuppressants or the medications used to keep the body from rejecting a new kidney.

These include:

• Tacrolimus
• Cyclosporine

Changes in how the body absorbs drugs could make them less effective or cause dangerous side effects.

“We’re not saying ‘no’ to cannabis,” said Dr. Rein. “But it’s important to have that discussion with your care team so they can help you use it safely and monitor your medications.”

The way you use cannabis matters—especially if you have kidney disease. Most people smoke it, but that’s not the safest option.

“Smoke inhalation is bad for health,” said Dr. Rein. “Whether you have kidney disease or not, you shouldn’t be inhaling smoke.”

Instead, consider other ways to use cannabis that don’t involve smoking.

These include:

• Edibles like gummies or baked goods
• Tinctures or drops placed under the tongue
• Topical products like lotions or balms that go on the skin

“Start at the lowest dose possible,” Dr. Rein said. “People are often surprised by how powerful some of these products are, especially edibles, which can take longer to work.”

CBD is available over the counter in oils, creams, drinks, and capsules. It’s often marketed as a safe, non-intoxicating product. But there are still concerns.

Here’s what to watch for:

• Some CBD products may contain small amounts of THC, even if the label says otherwise.
• Product labels are not always accurate, especially from companies that do not test their products.
• Switching between CBD brands or doses can lead to unexpected changes in drug levels, which could be dangerous for patients.

To reduce your risk:

• Choose brands with third-party testing and good quality standards.
• Look for USDA organic products made using Good Manufacturing Practices (GMP).
• Tell your kidney doctor if you plan to start, stop, or change your use of CBD. They may need to check your drug levels or adjust your medications.

Cannabis may help some people with kidney disease feel better—but it’s not right for everyone.

Talk to your healthcare provider about cannabis before trying it. Even if they aren’t a cannabis expert, they can still help you weigh the risks and benefits and keep your overall health in mind.

“We want to support our patients, not punish them,” said Dr. Rein. “So have that conversation. It’s always better to talk about it than to hide it.”

Get support from a trained professional. Call NKF Cares toll-free at 855.653.2273 or send a message here for help.