Medically Reviewed

Cannabidiol (CBD): Everything You Need to Know

We’ve got the 411 on whether CBD is really as magical as people make it out to be—and if it’s actually even legal.

Updated Feb 18, 2021

By

Jennifer Tzeses

Medical ReviewerAshley Maltz, M.D.

Our Experts: Daniele Piomelli, Ph.D.; Ryan Vandrey, Ph.D.; Hollis Karoly, Ph.D.

Daniele Piomelli, Ph.D.Director and Professor, Anatomy & Neurobiology Institute for the Study of Cannabis and School of Medicine University of California Irvine, CA

Ryan Vandrey, Ph.D.Associate Professor Behavioral Pharmacology Research Unit Johns Hopkins University School of Medicine Baltimore

Hollis Karoly, Ph.D.Research Associate Institute for Cognitive Science/Department of Psychology and Neuroscience Center for Innovation and Creativity at the University of Colorado Boulder, CO

It’s found everywhere from the fancy natural food market and the chain drugstore to the neighborhood pet shop—and heck, even the gas station around the corner. Hailed as a cure-all for just about every condition known to man, cannabidiol, more commonly known as CBD, is pervasive—like Millennial-pink pervasive.

In fact, according to a 2019 Gallup poll, one in seven Americans say they use CBD-based products. While legit everyone and their mother, grandmother, and best friend seem to be using CBD for pain, anxiety, and other ailments, many people still don’t know exactly what CBD is—and for good reason: There’s all kinds of confusion surrounding it. We’re here to clear the whole messy situation up.

To understand CBD, first you need to understand the cannabis plant. It’s a species that contains over 100 different chemical constituents called cannabinoids. The two primary cannabinoids are:

• Tetrahydrocannabinol (THC), the substance responsible for the psychoactive effects that make you feel high

• Cannabidiol (CBD), which has no psychoactive effects, but does likely interact with the body’s natural endocannabinoid system (more on this below)

Cannabis and marijuana are terms often used interchangeably but read: They are not the same thing. Think of cannabis as the mothership, where CBD, marijuana, and hemp come from. Marijuana only refers to parts and/or strain of the cannabis plant containing high levels of THC (more on this later).

People have widely reported that CBD is helpful for a slew of conditions: CBD for anxiety, CBD for insomnia, CBD for gastrointestinal problems, CBD for chronic pain, even CBD for neuroprotective properties to help treat symptoms of dementia. Keep in mind, CBD is FDA-approved for only one medication called Epidiolex, which treats the seizures resulting from two severe types of epilepsy, Lennox-Gastaut syndrome and Dravet syndrome, in patients two years of age and older. Using it for anything else is at your own risk, so always talk with your doctor before you try it.

Because it’s so mainstream, you might automatically assume CBD is legal. And it is (sort of) depending on the strain of cannabis plant it’s derived from. Here’s the deal:

• Cannabis that has 0.3% THC or less is known as hemp and is considered legal.

• Cannabis with 0.3% THC or greater, known as marijuana, is illegal depending on the state in which you live. At the federal level, marijuana is classified as a Schedule 1 drug, so any marijuana-derived product is considered illegal.

• States have the power to legalize both medical and recreational marijuana. And currently, 33 states have legalized medical marijuana, and 11 states and Washington, D.C. have legalized marijuana for recreational use for adults over 21.

Marijuana-derived CBD vs. Hemp-derived CBD

Here’s where things get really tricky: Though it can come from both hemp and marijuana, only CBD derived from hemp is legal everywhere. Marijuana-derived CBD is illegal (if you’re in a state where marijuana is illegal) because it’s classified as a controlled substance—regardless of the percentage of THC it contains.

And, to make things even more complicated, even if you live in a state where marijuana is legal, technically, you can’t cross over to the state next door with it because it’s still illegal at the federal level. Is your head spinning yet? We feel you. To clear up some confusion, here's a guide to the latest marijuana laws by state.

Believe it or not, we have a built-in biological system called the endocannabinoid system (ECS), (and no, it wasn’t designed specifically to process cannabis). It’s actually the body’s main regulatory system, meaning it keeps many functions in balance and sailing smoothly; it’s kind of like the body’s natural caretaker.

It’s made up of endocannabinoids, which our bodies naturally produce. These are molecules that closely resemble the cannabinoids found in the cannabis plant, cannabinoid receptors to which endocannabinoids bind, and enzymes, which are responsible for breaking down endocannabinoids once they’ve completed their job.

These three components manage a diverse range of physiological processes such as protecting neurons, regulating the immune system, influencing gastrointestinal functions, and impacting how we perceive pain. When something’s out of whack internally, endocannabinoids bind to receptors, which alert the ECS that certain functions aren’t working properly. For example, if the body is overheated, the ECS will tell the body to cool down by producing sweat.

When you consume THC, the main cannabinoid found in the cannabis plant, it interacts with two main receptors within the ECS, the CB1 receptor, found mostly in our brain and central nervous system, and the CB2 receptor, found mostly in the immune system. When THC binds to them, it causes psychoactive effects by disrupting mental and physical functioning like memory, concentration, and coordination.

For example, THC affects the functioning of the brain’s hippocampus and orbitofrontal cortex, which are areas responsible for creating new memories and shifting our attention from one thing to the next. As a result, marijuana can interfere with performing complicated tasks and cause impaired thinking. So while you might really be focusing on the insanely amazing glory of the clouds right now (and not much else), you’re probably also feeling pretty darn relaxed thanks to a boost to the brain’s pleasure centers. (Though in some people, higher doses of THC can spike anxiety instead of dulling it.)

Experts aren’t sure exactly how CBD, the other main cannabinoid found in the cannabis plant, works in the body, but it is thought to impact CB1 and CB2 functioning in a somewhat more indirect way than THC. However, they do have a theory as to why and how cannabinoids appear to target so many conditions: Because our own ECS is responsible for regulating systems throughout the whole body, it’s plausible that people would report a wide range of beneficial effects.

Many people swear up and down and sideways that CBD helps relieve whatever is ailing them. According to a study published in Cannabis and Cannabinoid Research, 62% of CBD users say they use the remedy to treat a specific medical condition vs. using it for general wellness. Though more research is needed—and when we say more, we mean a lot more—here’s a rundown on what we know so far about the conditions CBD might help.

According to studies done on rats by the National Institute on Drug Abuse, preclinical data showed CBD reduced the heart rate of angsty rodents and helped them chill out overall. Researchers say the CBD may have an effect on serotonin levels in the brain, which helps deliver a calming response.

Scientists also believe CBD can reverse the anxiety-producing effects of THC when it’s administered simultaneously in humans. And in some small-scale human studies, neuroimaging showed CBD reduced amygdala activation in the brain, the area that’s involved in processing emotions.

A 2018 study published in Cannabis and Cannabinoid Research reports that chronic pain is the most common condition CBD is used to treat. Though the exact way CBD relieves pain isn’t fully understood, scientists speculate it may block inflammatory agents in the body, dulling symptoms like prickling, tingling, and burning caused by damage to or inflammation of the nerves.

They also think CBD might interact with CB2 receptors found in the immune system, which are responsible for the body’s response to pain and inflammation. People report relief for the pain associated with conditions like arthritis, fibromyalgia, migraine, back, muscle, and multiple sclerosis. The other big benefit? It’s nonaddictive unlike other common treatments.

Experts aren’t entirely sure how CBD helps with sleeplessness, but they do think it may interact with receptors that affect the sleep/wake cycle. Also, because CBD may reduce the pain associated with many conditions, it can help those suffering experience a sounder snooze, so they stop tossing and turning in discomfort.

In a recent study published in The Permanente Journal, participants who suffered from both anxiety and insomnia were given 25mg of CBD in capsule form each day. After the first month, sleep improved in 66% of the subjects and anxiety improved in 79%, suggesting that by decreasing anxiety, sleep may also get better.

CBD for Gastrointestinal Symptoms

Researchers believe there are high levels of endocannabinoid receptors in the GI tract. Some small-scale animal studies have shown that CBD may have a beneficial effect on inflammatory bowel disease. In these studies, the use of cannabinoids given prophylactically helped reduced the patients’ abdominal pain and diarrhea, and it improved their quality of life overall by inhibiting the inflammatory reaction.

Because CBD is thought to have anti-inflammatory and anti-anxiety properties, it’s been reported to help minimize pain associated with cancer and the chemotherapy treatments used to treat cancer. There are several THC-based drugs approved to treat symptoms like nausea and vomiting produced by chemotherapy. These include Dronabinol (Marinol), which comes in capsule form and Nabilone (Cesamet), an oral synthetic cannabinoid that acts like THC.

CBD can be found in the cannabis flower (i.e., the cannabis products someone might smoke) as well as edible cannabis, oils, tinctures, lotions, and concentrated forms of cannabis (i.e., the cannabis someone might ingest through vaping). CBD oil, which is usually placed under the tongue, has been found to be most effective because it’s super concentrated and often works quickly, sometimes in under an hour.

CBD that’s absorbed by the digestive tract in capsule, food, or liquid forms is also recommended, but it may take longer to have an effect—up to two hours, however, it can also have an extended release.

Topical products, like lotions, gels, and balms, have been found to be effective for spot treatment for inflammation and painful joints.

Keep in mind, the science supporting the beneficial claims about CBD is limited—since researching it is highly regulated. And because of this, there is still a lot we don’t know about CBD pharmacology, dosing, or its effects. Scientists face several barriers in conducting research on CBD.

First, the one CBD-based medication that has been approved by the FDA, Epidiolex, contains a strain of CBD that’s very different from the CBD most people use. Since it’s controlled, it’s a pure sample of CBD and doesn’t have all the other plant-based compounds typically found in medical, recreational, and hemp-based forms.

These products are super tough to study, because every sample can widely differ from the next. Like most unregulated substances, it’s like the wild west out there, and you don’t know exactly what you’re getting, so talk with your doctor and dose slowly.

While it’s relatively safe, you may experience some CBD side effects. They can include:

• Nausea

• Fatigue

• Irritability

• Stomach upset

However, there's accumulating evidence that it can have significant drug interactions with certain other medications. This is because CBD is metabolized in the liver by a group of enzymes called CYPs. When cannabidiol is present in the body it can prevent CYPs from metabolizing other drugs, including those for:

• Heartburn

• Migraine

• Hypertension

To play it safe, if you’re using any other medication for any condition—even one not listed here—talk to your doctor before using CBD.

If you're looking to try CBD, talk with your primary care doctor about whether it might interact with any of the other drugs you’re currently taking. If they are reluctant to recommend it, seek out a doctor who specializes in integrative medicine or check with a national organization like the American Medical Marijuana Physicians Association for a provider in your area.

Buying a reputable batch can be tricky because the CBD products you can buy at stores (including those at cannabis dispensaries) are not regulated by the FDA, so any time you buy a CBD product, what you’re actually getting could contain different amounts of CBD than what is stated on the label. In fact, research has shown that the CBD content in almost 70% of CBD-labeled products available online may be mislabeled.

Experts recommend buying CBD that’s been third-party tested. Look for a stamp of quality assurance on the bottle and if it’s not there, scan the QR code with your smartphone or check the company’s website for a certificate of authenticity. Here, you can compare it to the label to make sure the concentration of CBD or THC matches. You’ll also want to check out what else the product contains:

• If the CBD is labeled full-spectrum, then it likely contains all of the other natural compounds found in the cannabis plant, including some THC.

• If it’s broad-spectrum, then it may contain all the other plant compounds except THC.

• If it‘s labeled CBD isolate, then it should be a pure form of CBD without any another plant compounds or THC (though again there’s no way to be absolutely sure).

As for where to buy it, your doctor may be able to give you some recommendations. Or if you live in a state where dispensaries are legal, usually their staff is knowledgeable. Always start by taking a small amount and wait to see how it affects you before upping your dose.