The FDA is working to answer questions about the science, safety, and quality of products containing cannabis and cannabis-derived compounds, particularly CBD. CBD oil has skyrocketed in popularity thanks to its purported calming effects. Here are nine ways studies suggest CBD oil could benefit your health. CBD oil is made from hemp plants. It may help treat pain, anxiety, and seizures. Here is what you should know before trying it.
What You Need to Know (And What We’re Working to Find Out) About Products Containing Cannabis or Cannabis-derived Compounds, Including CBD
The FDA is working to answer questions about the science, safety, and quality of products containing cannabis and cannabis-derived compounds, particularly CBD.
- Cannabis is a plant of the Cannabaceae family and contains more than eighty biologically active chemical compounds. The most commonly known compounds are delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). THC is the component that produces the “high” associated with marijuana use. Much interest has been seen around CBD and its potential related to health benefits.
- Marijuana is different from CBD. CBD is a single compound in the cannabis plant, and marijuana is a type of cannabis plant or plant material that contains many naturally occurring compounds, including CBD and THC.
- The FDA has approved only one CBD product, a prescription drug product to treat seizures associated with Lennox Gastaut syndrome (LGS), Dravet syndrome (DS), or tuberous sclerosis complex (TSC) in people one year of age and older.
- It is currently illegal to market CBD by adding it to a food or labeling it as a dietary supplement.
- The FDA has seen only limited data about CBD safety and these data point to real risks that need to be considered before taking CBD for any reason.
- Some CBD products are being marketed with unproven medical claims and are of unknown quality.
- The FDA will continue to update the public as it learns more about CBD.
Potential harm, side effects and unknowns
- CBD has the potential to harm you, and harm can happen even before you become aware of it.
- CBD can cause liver injury.
- CBD can affect how other drugs you are taking work, potentially causing serious side effects.
- Use of CBD with alcohol or other drugs that slow brain activity, such as those used to treat anxiety, panic, stress, or sleep disorders, increases the risk of sedation and drowsiness, which can lead to injuries.
- Male reproductive toxicity, or damage to fertility in males or male offspring of women who have been exposed, has been reported in studies of animals exposed to CBD.
- CBD can cause side effects that you might notice. These side effects should improve when CBD is stopped or when the amount used is reduced.
- Changes in alertness, most commonly experienced as somnolence (drowsiness or sleepiness).
- Gastrointestinal distress, most commonly experienced as diarrhea and/or decreased appetite.
- Changes in mood, most commonly experienced as irritability and agitation.
- There are many important aspects about CBD that we just don’t know, such as:
- What happens if you take CBD daily for sustained periods of time?
- What level of intake triggers the known risks associated with CBD?
- How do different methods of consumption affect intake (e.g., oral consumption, topical , smoking or vaping)?
- What is the effect of CBD on the developing brain (such as on children who take CBD)?
- What are the effects of CBD on the developing fetus or breastfed newborn?
- How does CBD interact with herbs and other plant materials?
- Does CBD cause male reproductive toxicity in humans, as has been reported in studies of animals?
Unanswered questions about the science, safety, and quality
You may have noticed that cannabidiol (CBD) seems to be available almost everywhere, and marketed as a variety of products including drugs, food, dietary supplements, cosmetics, and animal health products. Other than one prescription drug product to treat seizures associated with Lennox Gastaut syndrome (LGS), Dravet syndrome (DS), or tuberous sclerosis complex (TSC) in people one year of age and older, the U.S. Food and Drug Administration (FDA) has not approved any other CBD products, and there is very limited available information about CBD, including about its effects on the body.
The FDA recognizes the significant public interest in cannabis and cannabis-derived compounds, particularly CBD. However, there are many unanswered questions about the science, safety, and quality of products containing CBD. The agency is working on answering these questions through ongoing efforts including feedback from a recent FDA hearing and information and data gathering through a public docket.
Despite the 2018 Farm Bill removing hemp — defined as cannabis and cannabis derivatives with very low concentrations (no more than 0.3% on a dry weight basis) of THC — from the definition of marijuana in the Controlled Substances Act, CBD products are still subject to the same laws and requirements as FDA-regulated products that contain any other substance.
The FDA is concerned that people may mistakenly believe that using CBD “can’t hurt.” The agency wants to be clear that we have seen only limited data about CBD’s safety and these data point to real risks that need to be considered. As part of the drug review and approval process for the prescription drug containing CBD, it was determined that the risks are outweighed by the benefits of the approved drug for the particular population for which it was intended. Consumer use of any CBD products should always be discussed with a healthcare provider. Consumers should be aware of the potential risks associated with using CBD products. Some of these can occur without your awareness, such as:
- Liver Injury: During its review of the marketing application for Epidiolex — a purified form of CBD that the FDA approved in 2018 for use in the treatment of two rare and severe seizure disorders — the FDA identified certain safety risks, including the potential for liver injury. This serious risk can be managed when an FDA-approved CBD drug product is taken under medical supervision, but it is less clear how it might be managed when CBD is used far more widely, without medical supervision, and not in accordance with FDA-approved labeling. Although this risk was increased when taken with other drugs that impact the liver, signs of liver injury were seen also in patients not on those drugs. The occurrence of this liver injury was identified through blood tests, as is often the case with early problems with the liver. Liver injury was also seen in other studies of CBD in published literature. We are concerned about potential liver injury associated with CBD use that could go undetected if not monitored by a healthcare provider.
- Drug Interactions: Information from studies of the FDA-approved CBD drug Epidiolex show that there is a risk of CBD impacting other medicines you take – or that other medicines you take could impact the dose of CBD that can safely be used. Taking CBD with other medications may increase or decrease the effects of the other medications. This may lead to an increased chance of adverse effects from, or decreased effectiveness of, the other medications. Drug interactions were also seen in other studies of CBD in published literature. We are concerned about the potential safety of taking other medicines with CBD when not being monitored by a healthcare provider. In addition, there is limited research on the interactions between CBD products and herbs or other plant-based products in dietary supplements. Consumers should use caution when combining CBD products with herbs or dietary supplements.
- Male Reproductive Toxicity: Studies in laboratory animals showed male reproductive toxicity, including in the male offspring of CBD-treated pregnant females. The changes seen include decrease in testicular size, inhibition of sperm growth and development, and decreased circulating testosterone, among others. Because these findings were only seen in animals, it is not yet clear what these findings mean for human patients and the impact it could have on men (or the male children of pregnant women) who take CBD. For instance, these findings raise the concern that CBD could negatively affect a man’s fertility. Further testing and evaluation are needed to better understand this potential risk.
In addition, CBD can be the cause of side effects that you might notice. These side effects should improve when CBD is stopped or when the amount used is reduced. This could include changes in alertness, most commonly experienced as somnolence (sleepiness), but this could also include insomnia; gastrointestinal distress, most commonly experienced as diarrhea and/or decreased appetite but could also include abdominal pain or upset stomach; and changes in mood, most commonly experienced as irritability and agitation.
The FDA is actively working to learn more about the safety of CBD and CBD products, including the risks identified above and other topics, such as:
- Cumulative Exposure: The cumulative exposure to CBD if people access it across a broad range of consumer products. For example, what happens if you eat food with CBD in it, use CBD-infused skin cream and take other CBD-based products on the same day? How much CBD is absorbed from your skin cream? What if you use these products daily for a week or a month?
- Special Populations: The effects of CBD on other special populations (e.g., the elderly, children, adolescents, pregnant and lactating women).
- CBD and Animals: The safety of CBD use in pets and other animals, including considerations of species, breed, or class and the safety of the resulting human food products (e.g., meat milk, or eggs) from food-producing species.
Unproven medical claims, unsafe manufacturing practices
Some CBD Products are Being Marketed with Unproven Medical Claims and Could be Produced with Unsafe Manufacturing Practices
Unlike the FDA-approved CBD drug product, unapproved CBD products, which could include cosmetics, foods, products marketed as dietary supplements, and any other product (other than Epidiolex) making therapeutic claims, have not been subject to FDA evaluation regarding whether they are effective to treat a particular disease or have other effects that may be claimed. In addition, they have not been evaluated by the FDA to determine what the proper dosage is, how they could interact with other drugs or foods, or whether they have dangerous side effects or other safety concerns.
Misleading, unproven, or false claims associated with CBD products may lead consumers to put off getting important medical care, such as proper diagnosis, treatment, and supportive care. For that reason, it’s important to talk to your doctor about the best way to treat diseases or conditions with available FDA-approved treatment options.
In addition to safety risks and unproven claims, the quality of many CBD products may also be in question. The FDA is also concerned that a lack of appropriate processing controls and practices can put consumers at additional risks. For example, the agency has tested the chemical content of cannabinoid compounds in some of the products, and many were found to not contain the levels of CBD they claimed. We are also investigating reports of CBD potentially containing unsafe levels of contaminants (e.g., pesticides, heavy metals, THC).
CBD products are also being marketed for pets and other animals. The FDA has not approved CBD for any use in animals and the concerns regarding CBD products with unproven medical claims and of unknown quality equally apply to CBD products marketed for animals. The FDA recommends pet owners talk with their veterinarians about appropriate treatment options for their pets.
The FDA’s top priority is to protect the public health. This priority includes making sure consumers know about products that put their health and safety at greatest risk, such as those claiming to prevent, diagnose, treat, mitigate, or cure serious diseases. For example, the agency has warned companies to stop selling CBD products they claim are intended to prevent, diagnose, treat, mitigate, or cure serious diseases such as cancer, Alzheimer’s disease, psychiatric disorders and diabetes. While we have focused on these types of products, we will continue to monitor the marketplace for any product that poses a risk to public health, including those with dangerous contaminants, those marketed to vulnerable populations, and products that otherwise put the public health at risk.
Evaluation of the regulatory frameworks
The FDA is Continuing to Evaluate the Regulatory Frameworks for Products Containing Cannabis and Cannabis-Derived Compounds
The FDA continues to believe the drug approval process represents the best way to ensure that safe and effective new medicines, including any drugs derived from cannabis, are available to patients in need of appropriate medical therapy. The agency is committed to supporting the development of new drugs, including cannabis and cannabis-derived drugs, through the investigational new drug and drug approval process.
We are aware that there may be some products on the market that add CBD to a food or label CBD as a dietary supplement. Under federal law, it is illegal to market CBD this way.
The FDA is evaluating the regulatory frameworks that apply to certain cannabis-derived products that are intended for non-drug uses, including whether and/or how the FDA might consider updating its regulations, as well as whether potential legislation might be appropriate. The information we have underscores the need for further study and high quality, scientific information about the safety and potential uses of CBD.
The FDA is committed to setting sound, science-based policy. The FDA is raising these safety, marketing, and labeling concerns because we want you to know what we know. We encourage consumers to think carefully before exposing themselves, their family, or their pets, to any product, especially products like CBD, which may have potential risks, be of unknown quality, and have unproven benefits.
Our Consumer Update includes a practical summary of what we know to date. As we learn more, our goal is to update you with the information you need to make informed choices about CBD products. Also, as the regulatory pathways are clarified we will take care to inform all stakeholders as quickly as possible.
CBD Oil: 9 Science-Backed Benefits
Dr. Bindiya Gandhi is an integrative medicine physician with expertise in functional and holistic medicine based in Atlanta, Georgia.
Commissions we earn from partner links on this page do not affect our opinions or evaluations. Our editorial content is based on thorough research and guidance from the Forbes Health Advisory Board.
Cannabidiol, or CBD, is a chemical compound found in the cannabis sativa plant. When applied topically or consumed through smoke inhalation or edible consumption, CBD interacts with neuroreceptors in your endocannabinoid system, which sends signals between your cells to help regulate your movement, mood, homeostasis and immune system.
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CBD is often extracted from the cannabis sativa plant in oil form and mixed with an inert carrier oil like hemp seed oil for consumption. In fact, of the 60% of U.S. adults who report having used CBD before, 55% of them use CBD oils and tinctures specifically, according to a recent Forbes Health survey of 2,000 U.S. adults conducted by OnePoll.
CBD research is growing, too. Here are nine ways studies suggest CBD oil could benefit your health.
1. Offset Anxiety and Depression
CBD’s ability to calm is perhaps its most popular effect and the reason its use is so widespread. A 2017 study in the Brazilian Journal of Psychiatry tested the anxiety levels of 57 men in a simulated public speaking test. Some received a placebo while others received either 150 milligrams, 300 milligrams or 600 milligrams of CBD before their speeches. Those who received 300 milligrams of CBD experienced significantly reduced anxiety during the test compared to those who received the placebo. Interestingly, participants who received either 150 or 600 milligrams of CBD experienced more anxiety during the test than the 300 milligrams group.
Meanwhile, at least one study in mice revealed CBD had effects similar to the antidepressant imipramine. Human trials are needed, though, to confirm whether CBD can induce this same antidepressant reaction in our bodies.
2. Treat Select Epilepsy Syndromes
In some instances, CBD can be used to treat epileptic seizures.
In 2018, the Food and Drug Administration (FDA) approved the use of CBD under the brand name Epidiolex to treat seizures resulting from Lennox-Gastaut syndrome and Dravet syndrome—two rare forms of epilepsy—in patients at least 2 years old.
Three well-vetted studies provide the basis of support for the FDA’s decision. In these trials, 516 patients with Lennox-Gastaut syndrome or Dravet syndrome received either Epidiolex or a placebo. Epidiolex, when taken along with other prescribed medications, decreased the frequency of participants’ seizures compared to the placebo.
3. Reduce PTSD Symptoms
In a small 2018 study in the Journal of Alternative and Complementary Medicine, 11 people with post-traumatic stress disorder (PTSD) received CBD along with routine psychiatric care for eight weeks in an outpatient psychiatric clinic. Ten of the 11 experienced a decrease in their PTSD symptoms. CBD was generally well tolerated, the researchers write.
Margaret Rajnic, a doctor of nursing practice experienced in medical cannabis and CBD, emphasizes the importance of using therapy in tandem with any type of cannabis or CBD for PTSD. “There is an amount of therapy that is needed for PTSD,” she says. “But CBD will give you that little bit of decreased anxiety.”
Four other human trials from 2012 to 2016 suggest CBD reduces PTSD symptoms, although some include THC, or tetrahydrocannabinol, the main mind-altering element in cannabis. When THC and CBD work together, they create what’s called an “entourage effect,” complementing each other’s benefits and potency. For example, taking the same dose of THC and CBD together tempers the “high” from THC, while just a little THC paired with more CBD enhances the effects of the CBD.
4. Treat Opioid Addiction
Some studies—both preclinical animal and human clinical trials—suggest CBD could be used to help treat people who are dependent on opioids.
In one such study, researchers administered CBD to people with heroin use disorder. Over the course of a week, CBD significantly reduced heroin users’ cue-induced cravings, withdrawal anxiety, resting heart rate and salivary cortisol levels. No serious adverse effects were found.
Other studies find CBD helpful in reducing various psychiatric and medical symptoms like anxiety, insomnia and pain in patients with substance use disorders, indicating that CBD may be an effective treatment for opioid addiction. However, further studies are necessary.
5. Alleviate ALS Symptoms
Amyotrophic lateral sclerosis (ALS) is a disease that causes nerve cells in the brain and spinal cord to deteriorate, resulting in loss of muscle control that worsens over time. It’s not yet understood exactly why ALS occurs, although it can be hereditary in some cases. There’s no known cure, and there are only two FDA-approved medications to help treat ALS symptoms.
Research suggests people with ALS can benefit from the entourage effect created by the combination of THC and CBD, similar to people with PTSD. In a 2019 study, patients received a combination of THC and CBD in varying doses depending on their needs and preferences. Those with mild, moderate or severe spasticity (muscle tightness and stiffness) due to ALS reported high levels of satisfaction with the treatment, and those with moderate to severe spasticity reported higher satisfaction rates than those with mild spasticity.
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6. Relieve Unmanageable Pain
In 2005, Canada approved the use of Sativex, an oromucosal (absorbed in the lining of the mouth) spray with equal proportions of THC and CBD, for the treatment of multiple sclerosis-related central neuropathic pain. In 2007, Canada approved the medicine’s use again for cancer pain that proved unresponsive to other medications.
Meanwhile, continued studies in the U.S. indicate CBD is effective in treating chronic, non-cancer pain. In one 2020 study, researchers administered CBD topically to a group of patients with symptomatic peripheral neuropathy (a result of brain nerve and spinal cord nerve damage) while another group with the same condition received a placebo. Results showed a significant reduction in intense, sharp pains and cold, itchy sensations in those who used the topical CBD compared to those who used the placebo. No participants reported adverse side effects.
When introduced topically, CBD oil doesn’t affect the systemic issue as it might if it were introduced directly into the bloodstream. Instead, topical CBD is more localized and treats pain in a certain area. Since it’s more direct, it may have a more pronounced effect.
7. Ease Diabetic Complications
For starters, tests on human cells found that CBD helps reduce the effects of high glucose levels on other cells in the body, which typically precedes the development of diabetes and various complications. Researchers concluded that with further studies, CBD could have significant benefits when used in patients with diabetes, diabetic complications and plaque buildup in artery walls.
In another small study, 13 patients with type 2 diabetes who weren’t on insulin treatment were given both CBD and a placebo (in lieu of insulin). Researchers found CBD decreased their levels of resistin (which causes resistance to insulin, the protein that regulates sugar levels) and increased their levels of glucose-dependent insulinotropic peptide (a hormone that ensures a sufficient release of insulin from digested food) compared to their baselines before they started the test. These results suggest CBD could be a natural treatment for diabetes by helping the body regulate insulin-related hormone levels.
8. Protect Against Neurological Disease
Preclinical and clinical studies show that CBD has antioxidant and anti-inflammatory properties. Researchers deduce these characteristics can provide significant neuroprotection, or protection against numerous pathological disorders.
Several preclinical studies suggest CBD can produce beneficial effects against Parkinson’s disease, Alzheimer’s disease and multiple sclerosis. Huntington’s disease and cerebral ischemia were also tested, although significant positive results were not recorded. Further clinical studies are needed to confirm CBD’s benefits when used as a treatment for these disorders.
9. Inhibit Arthritis Symptoms
Arthritis involves the deterioration of the tissues in and around your joints. There are several types of arthritis, and symptoms include pain, stiffness and loss of motion. Arthritis treatment usually targets pain relief and improved joint function.
A 2006 study found that Sativex—a CBD-based botanical drug approved in the United Kingdom in 2010—promoted statistically significant improvements in quality of sleep, pain during movement and pain at rest in patients with rheumatoid arthritis when compared to a placebo. It was the first controlled trial of Sativex as a treatment for rheumatoid arthritis, involving 58 patients. CBD was found to have a pain-relieving effect, as well as an ability to suppress disease activity.
In 2018, in a study of more localized treatment, researchers administered a synthetic CBD gel in either 250-milligram or 500-milligram doses daily or a placebo to patients with knee pain due to osteoarthritis. Patients also stopped taking any other anti-inflammatory medications or painkillers, with the exception of acetaminophen, before and during the study period.
The results were interesting, although not entirely conclusive. On one hand, those treated with CBD did not experience much change in pain when compared with placebo patients. On the other hand, there were statistically significant differences between the group receiving the 250-milligram dose and the placebo group when measuring the average weekly improvement of their worst pain levels and their WOMAC (Western Ontario and McMaster Universities Arthritis Index) physical function rating. Additionally, men seemed to benefit from CBD more significantly than women in this test.
Forbes Health covers CBD and cannabis products in accordance with FTC guidelines. Learn more about Forbes Health’s practices and policies regarding how we cover CBD and cannabis as a publisher.
CBD Oil Benefits vs. Side Effects
While it may be helpful, it may not be safe for all
Cathy Wong is a nutritionist and wellness expert. Her work is regularly featured in media such as First For Women, Woman’s World, and Natural Health.
Verywell Health articles are reviewed by board-certified physicians and healthcare professionals. These medical reviewers confirm the content is thorough and accurate, reflecting the latest evidence-based research. Content is reviewed before publication and upon substantial updates. Learn more.
Meredith Bull, ND, is a licensed naturopathic doctor with a private practice in Los Angeles, California.
CBD oil is said to have a variety of possible health benefits. It is used as an appetite stimulant, a sleep aid, a treatment for skin conditions like eczema and psoriasis, for relief of pain, to prevent seizures, and much more.
Though derived from cannabis, the same plants grown for marijuana, CBD oil is not he same as pot. But that doesn’t mean that CBD oil is 100% safe. Some possible side effects, like dry mouth, may be fairly minor. Others, like anxiety, are potentially more significant. And certain potential side effects may even make using CBD oil inadvisable for some people.
This article goes over what CBD is used for, the possible side effects, and what you should look for if you choose to buy CBD.
What Exactly Is CBD Oil?
CBD oil is a hemp plant extract known as cannabidiol mixed with a base (carrier) oil like coconut oil or hemp seed oil. CBD oil comes from Cannabis indica and Cannabis sativa plants.
CBD Oil Benefits
People who support the use of CBD claim that CBD oil benefits people with a variety of health problems. CBD oil is said to be good for:
- Drug use and withdrawal
- High blood pressure
- Muscle spasms
- Poor appetite
- Skin conditions like eczema and psoriasis
As CBD has gained popularity, researchers have been trying to study it more. Still, there has not yet been a lot of clinical research focused on finding evidence to back up these health claims.
Here’s a deeper dive into what is known about a few of the purported health benefits of CBD oil.
A 2015 review of research that was published in the journal Neurotherapeutics suggested that CBD might help treat anxiety disorders.
The study authors reported that CBD had previously shown powerful anxiety-relieving effects in animal research—and the results were kind of surprising.
In most of the studies, lower doses of CBD (10 milligrams per kilogram, mg/kg, or less) improved some symptoms of anxiety, while higher doses (100 mg/kg or more) had almost no effect.
The way that CBD acts in the brain could explain why this happens. In low doses, CBD might act the same as the surrounding molecules that normally bind to the receptor that “turns up” their signaling. However, at higher doses, too much activity at this receptor site could produce the opposite effect.
There have not been many trials to look at CBD’s anxiety-relieving effects in humans. However, one was a 2019 study published in the Brazilian Journal of Psychiatry.
For the study, 57 men took either CBD oil or a sugar pill with no CBD in it (placebo) before a public-speaking event.
The researchers assessed the participants’ anxiety levels using measures like blood pressure and heart rate. The researchers also used a reliable test for mood states called the Visual Analog Mood Scale (VAMS).
The men who took 300 milligrams (mg) of CBD oil reported less anxiety than the men who were given a placebo; however, the men who took 100 mg or 600 mg of CBD oil did not experience the same effects.
CBD oil might help people with substance use disorder, according to a 2015 review published in the journal Substance Abuse.
The review looked at the findings from 14 published studies. Nine of the studies looked at the effects of CBD on animals and five looked at the effects on humans.
The researchers reported that CBD showed promise for treating people with opioid, cocaine, or psychostimulant use disorders.
However, the effects of CBD were quite different depending on the substance. For example, CBD without THC did not decrease withdrawal symptoms related to opioid use.
On the other hand, it did reduce drug-seeking behaviors in people using cocaine, methamphetamine, and other similar drugs.
Some experts suggest that CBD could help treat cannabis and nicotine dependence, but more research is needed to provide this theory.
Some studies have suggested that CBD oil may benefit the skin.
A 2020 paper, for example, found that CBD oil may help reduce inflammation, which could be useful for treating a variety of skin conditions including allergic dermatitis, acne, and psoriasis.
Proponents say CBD oil has benefits for people with cancer. Although some studies have shown promise, there have been no large studies proving the benefits of CBD oil as a cancer treatment.
Other studies suggest that CBD might interact with cancer drugs.
If you have cancer and are considering CBD, talk to your oncologist first about whether or not it is safe for you to use.
High Blood Pressure
A 2017 study found that CBD oil may reduce the risk of heart disease because it can lower high blood pressure in some people.
For the study, nine healthy men took either 600 mg of CBD or the same dose of a placebo. The men who took CBD had lower blood pressure before and after experiencing stressors like exercise or extreme cold.
The study also looked at the amount of blood remaining in the heart after a heartbeat (stroke volume). The stroke volume in the men who took CBD was lower than in was in the placebo group, meaning their hearts were pumping more efficiently.
The study suggested that CBD oil could be a complementary therapy for people with high blood pressure that is affected by stress and anxiety.
However, there is no evidence that CBD oil can treat high blood pressure on its own or prevent it in people at risk. While stress can complicate high blood pressure, it does not cause it.
Proponents say CBD oil has benefits as a sleep aid, but research so far is inconclusive.
A 2017 review pointed out that many studies have been small and limited. However, the authors also noted that because cannabinoids seem to have an effect on the sleep-wake cycle, their potential as a sleep aid is worthy of additional research.
In June 2018, the Food and Drug Administration (FDA) approved a CBD oral solution called Epidiolex.
Epidiolex is used to treat two rare forms of epilepsy in children under the age of 2: Dravet syndrome and Lennox-Gastaut syndrome. These are very rare genetic disorders that cause lifelong seizures starting in the first year of life.
Other than for these two disorders, CBD’s effectiveness for treating seizures is not known. Even with Epidiolex, it’s not clear if the anti-seizure effects are from CBD or another factor.
However, there is some evidence that CBD interacts with seizure medicines like Onfi (clobazam) and raises their concentration in the blood. More research is needed to understand the link.
Possible CBD Oil Side Effects
Clinical research has shown that CBD oil can cause side effects. The specific side effects and their severity varies from one person to the next and from one type of CBD to another.
Some common CBD side effects people report include:
- Changes in appetite
- Changes in mood
- Dizziness or fatigue
- Dry mouth
Do not drive or use heavy machinery when taking CBD oil—especially when you first start using it or switch to a new brand. Remember that some products do contain THC, even in small amounts.
Your healthcare practitioner may advise against using CBD oil if you:
- Have liver disease: CBD oil may increase liver enzymes, which is a marker of liver inflammation. Talk with your healthcare provider before taking CBD oil. You may need to have your liver enzymes checked regularly if you decide to use it.
- Have eye issues: CBD oil may also cause eye-related side effects. A 2018 study found that it may increase pressure inside the eyes. For people with glaucoma, this can make the condition worse. Some people also report dry eyes as a side effect of CBD oil.
- Are pregnant or nursing: You should not use CBD oil if you’re pregnant or breastfeeding. Even though the effects of CBD are not fully understood, it does pass through the placenta.
The American Academy of Pediatrics (AAP) further states that pregnant people should not use marijuana because of the potential risks to a developing fetus.
Can CBD Oil Get You High?
CBD oil does not get you high. Although it is from a plant that is in the same family as the marijuana plant, it does not contain tetrahydrocannabinol (THC), the compound responsible for this feeling.
|A component of the hemp plant||Separate plant in the hemp family that contains CBD and hundreds of other compounds.|
|No or trace amounts of THC||Significant amounts of THC|
|Works receptors in the brain, but not those that induce psychoactive effects (e.g., opioid receptors that help control pain, glycine receptors that impact mood control)||THC binds to cannabinoid receptors in the brain to create “high” feeling|
What CBD Oil Can Interact With
CBD oil can interact with medications, including many that are used to treat epilepsy. One of the reasons for this has to do with how your body breaks down (metabolizes) drugs.
Cytochrome P450 (CYP450) is an enzyme your body uses to break down some drugs. CBD oil can block CYP450. That means that taking CBD oil with these drugs could make them have a stronger effect than you need or make them not work at all.
Drugs that could potentially interact with CBD include:
- Anti-arrhythmia drugs like quinidine
- Anticonvulsants like Tegretol (carbamazepine) and Trileptal (oxcarbazepine)
- Antifungal drugs like Nizoral (ketoconazole) and Vfend (voriconazole)
- Antipsychotic drugs like Orap (pimozide)
- Atypical antidepressants like Remeron (mirtazapine)
- Benzodiazepine sedatives like Klonopin (clonazepam) and Halcion (triazolam)
- Immune-suppressive drugs like Sandimmune (cyclosporine)
- Macrolide antibiotics like clarithromycin and telithromycin
- Migraine medicine like Ergomar (ergotamine)
- Opioid painkillers like Duragesic (fentanyl) and alfentanil
- Rifampin-based drugs used to treat tuberculosis
Always tell your healthcare provider and pharmacist about all the medicines you take, including prescription, over-the-counter (OTC), herbal, or recreational drugs.
The interactions between these medications and CBD are often mild and you might not have to change your treatment. However, in some cases, you might have to change medications or space out your doses to avoid a reaction. Never change or stop medication without talking to your provider.
What’s a Safe Dosage of CBD Oil?
There are no guidelines for use, nor is there a “correct” dose of CBD oil. That said, the average dose range is from 5 mg to 25 mg.
Available forms include:
- Tinctures (CBD oil mixed with a base oil)
Which you choose largely comes down to your preference and what you hope to get in terms of effects. For example, putting the oil under your tongue can produce effects more quickly than swallowing a capsule that needs to be digested.
Each product works a bit differently, depending on the form, so it’s important to follow the provided directions.
How to Calculate a CBD Dose
Sprays, gummies, and capsules are easy to use because their doses are pre-measured.
Tinctures are a bit more challenging. Most oils come in 30-milliliter (mL) bottles and include a dropper cap to help you measure.
But some tinctures have concentrations of 1,500 mg per 30 mL, while others have 3,000 mg per mL or more. That means figuring out the exact amount of CBD per milliliter of oil requires a little math.
To determine an exact dose of CBD, remember that each drop of oil equals 0.05 mL of fluid. This means that a 30-mL bottle of CBD oil will have about 600 drops in it.
If the concentration of the tincture is 1,500 mg per mL, one drop would have 2.5 mg of CBD in it (1,500 mg ÷ 600 drops = 2.5 mg).
Safer Buying Practices
Remember that CBD oils are unregulated. There’s no guarantee that a product is what it claims to be on its packaging. You also can’t know for sure that it’s safe and effective.
A 2017 study reported that only 31% of CBD products sold online were correctly labeled. Most had less CBD in them than was advertised, and 21% had significant amounts of THC.
If you are interested in buying CBD products, here are a few tips that can help you make the best choice:
- Buy American: Domestically produced CBD oil might be a safer option than those that have been imported.
- Go organic: Brands certified organic by the U.S. Department of Agriculture (USDA) are less likely to expose you to pesticides and other harmful chemicals.
- Read the product label: Don’t assume that every ingredient on the product label is natural. CBD products can also have preservatives, flavorings, or thinning agents in them. If you don’t recognize an ingredient, ask the dispenser what it is or check online.
Frequently Asked Questions
CBD oil comes in different forms:
- Isolates contain only CBD.
- Broad-spectrum oils have nearly all of the components of the plant (e.g., proteins, flavonoids, terpenes, and chlorophyll), but do not have THC. oils have all the compounds including THC (up to 0.3%)
Alternative medicine practitioners believe that the compounds provide more health benefits, but the is a lack of evidence to support these claims.
Not necessarily. While the names are sometimes used interchangeably, hemp oil can also refer to hemp seed oil, which is used for cooking, food production, and skincare products. CBD oil is made from the leaves, stems, buds, and flowers of the Cannabis indica or Cannabis sativa plant. It should contain less than 0.3% THC. Hemp oil is made from the seeds of Cannabis sativa and does not have TCH in it.
It would be hard to overdose on CBD oil. Research has shown that human tolerance for CBD is very high. One study reported the toxic dose would be about 20,000 mg taken at one time.
It depends on where you live, the type of product, how it was sourced, and its intended purpose (medical or recreational). In many states, you must be 18 or 21 to buy CBD oil. Check your state’s laws.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Cathy Wong
Cathy Wong is a nutritionist and wellness expert. Her work is regularly featured in media such as First For Women, Woman’s World, and Natural Health.