Cannabidiol (cbd)
OTHER NAME(S): cannabidiol, CBD
Overview
Cannabidiol (CBD) is a cannabinoid that comes from Cannabis sativa (cannabis). It is not psychoactive, which means it does not have brain-altering effects. There is interest in using CBD products for many reasons, including pain, anxiety, stress, and insomnia, but its benefits for any use are not well defined. Common side effects include diarrhea, vomiting, loss of appetite, sleepiness, and trouble sleeping. Serious side effects are less common and include liver damage, suicidal thoughts, and a condition called cannabinoid hyperemesis syndrome (CHS). Do not confuse CBD products that are available over-the-counter with prescription CBD (Epidiolex). These products are not the same. Before using CBD, make sure to tell your health care provider about any health conditions you have or medicines you are taking.
Uses
What is cannabidiol (CBD) used for?
CBD products are taken by mouth and applied to the skin for various reasons, but their benefits are not well defined. Some common reasons that people use CBD include the following.
- Anxiety
- Pain
- Skin conditions
- Trouble sleeping (insomnia)
- To help manage stress
CBD is also available as a prescription medicine for certain types of seizures. See Epidiolex for more information.
Note: Nonprescription CBD products are not approved by the FDA. The FDA also does not consider CBD to be a legal dietary ingredient in the U.S. Learn more about the legal status of CBD here.
How does CBD work (mechanism of action)?
Cannabidiol (CBD) is a cannabinoid found in the Cannabis sativa plant. Cannabis[1] contains over 100 different cannabinoids. Some cannabinoids, such as delta-9-tetrahydrocannabinol (THC)[2] , are psychoactive, which means that they cause brain-altering effects that can make you feel “high.” However, most cannabinoids are considered nonpsychoactive and do not have this effect. CBD is a nonpsychoactive cannabinoid.
There is interest in using over-the-counter CBD products for a wide range of purposes, including for anxiety, stress, pain, and trouble sleeping. But the benefits of CBD for these uses are not well defined. Some people report improvement in their symptoms while using CBD, and some studies have shown small benefits in certain people. But other studies have shown no benefits when CBD is compared with a placebo (a product containing no medicine).
Some CBD products are intended to be applied to the skin. But there is no evidence that CBD can pass through the skin and into the body. The benefits of CBD for skin health are also not well defined.
A prescription form of CBD, Epidiolex, has been approved in the U.S. for the treatment of certain types of seizures. This prescription form of CBD is different from the CBD products that can be purchased over-the-counter. The products that can be purchased over-the-counter have not been tested to confirm that they contain the ingredients or the amounts stated on their labels. Over-the-counter CBD products should not be used to replace treatment with prescription CBD.
How should I store CBD?
You should store CBD according to the product label. Most herbal products should be kept in a cool, dry location that is out of the reach of children and pets and not in direct sunlight.
Side Effects
What are the most common side effects of CBD?
The most common side effects of taking CBD by mouth are listed below. These side effects may vary depending on the specific product you are taking and may be more common with higher doses. Tell your health care provider if you have any of these side effects that bother you.
- Diarrhea
- Liver damage (see below)
- Loss of appetite
- Sleepiness or trouble sleeping
- Vomiting
There may be other side effects of CBD that are not listed here. Contact your health care provider if you think you are having a side effect of an herbal product. In the U.S., you can report side effects to the FDA at www.safetyreporting.hhs.gov or by calling 888-SAFEFOOD (888-723-3366). In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.
What are the serious side effects of CBD?
While less common, the most serious side effects of CBD are described below, along with what to do if they happen.
Severe Allergic Reactions. CBD may cause allergic reactions, which can be serious. Stop using CBD and get help right away if you have any of the following symptoms of a serious allergic reaction.
- Breathing problems or wheezing
- Racing heart
- Fever or general ill feeling
- Swollen lymph nodes
- Swelling of the face, lips, mouth, tongue, or throat
- Trouble swallowing or throat tightness
- Itching or skin rash
- Bumps on the skin called hives that can be red, pink, white, or brown depending on your skin tone
- Nausea or vomiting
- Dizziness, feeling lightheaded, or fainting
- Stomach cramps
- Joint pain
Cannabinoid Hyperemesis Syndrome (CHS).Some people who use CBD, cannabis, or other cannabinoids may develop a condition called cannabinoid hyperemesis syndrome (CHS). This condition can happen at any time while taking CBD and may be more likely in people who have regularly used it for more than a year. CHS causes severe nausea, vomiting, and stomach pain. This can lead to dehydration and changes in electrolyte levels that can be life-threatening. If you have severe nausea or vomiting that does not go away, get medical help right away. If you think you may have CHS, speak with your health care provider. Stopping all use of CBD, cannabis, or other cannabinoids is the only known cure for CHS.
Liver Damage. Liver damage, also called hepatotoxicity, can happen when taking CBD by mouth. Call your health care provider right away if you have any of the following symptoms of liver damage.
- Nausea or vomiting
- Stomach or belly pain
- Fever
- Weakness or unusual tiredness
- Itching
- Loss of appetite
- Light-colored poop
- Dark-colored urine (pee)
- Your skin or the whites of your eyes turning yellowish in color (called jaundice)
Suicidal Thoughts and Actions.Taking CBD by mouth may cause suicidal thoughts or actions in a small number of people. If you are about to harm yourself, call 911 or call or text 988, the Suicide & Crisis Lifeline. Call your health care provider right away if you have any of the following symptoms.
- New or increased thoughts of suicide or death
- Suicide attempt
- New or increased feelings of anxiety, depression, or other unusual changes in mood or behavior
Precautions
Who should not use CBD?
Allergies to Ingredients. People who are allergic to any of the following should not use CBD.
- Cannabidiol
- CBD
- Any of the ingredients in the specific product
Ask your health care provider if you are not sure what ingredients are in a CBD product.
What should I know about CBD before using it?
The FDA does not consider CBD to be a legal dietary ingredient. However, CBD products are still available for purchase in many places. These products are not regulated and have not been tested to confirm that they contain the ingredients stated on their labels.
Read and follow the directions on the specific product you are using, or use it as recommended by your health care provider.
Keep CBD out of the reach of children and pets.
CBD can affect your alertness or coordination. Do not drive or do other activities that require alertness or coordination until you know how CBD affects you.
Food changes the way that your body absorbs CBD. When taking CBD by mouth, it is best to always take it the same way, either with or without food.
If you are taking CBD as a gummy, chew the gummy well before swallowing. If you are taking a liquid CBD product, use an accurate measuring device to measure your dose. A household spoon is not an accurate measuring device and may cause you to take the wrong dose. Ask your pharmacist what measuring device to use.
CBD products may be contaminated with other cannabinoids, such as delta-9-tetrahydrocannabinol (THC). This can cause a drug test (urine or blood) for cannabis, marijuana, or THC to come back positive. As the main psychoactive chemical in cannabis, THC can also cause unwanted effects and side effects. If you are pregnant or breastfeeding, THC can cause unwanted effects and side effects for your baby. Talk to your health care provider if you have concerns.
CBD comes from the Cannabis sativa plant. This plant is a phytoremediator, which means that it is able to pull toxins and heavy metals out of the soil where it grows. These toxins and heavy metals are pulled into the plant and may be found in products made from the plant. This means that CBD products may be at high risk of contamination with heavy metals and other harmful chemicals.
What should I tell my health care provider before using CBD?
Tell your health care provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them know if CBD is right for you.
In particular, make sure that you discuss any of the following.
Current and Past Health Conditions.Tell your health care provider if you have any of the following.
- Liver problems
- Mental health problems, including depression, mood problems, or thoughts of suicide
- Substance use disorder
- Alcohol use disorder
Other Medicines and Supplements.CBD may interact with other medicines and supplements. Before using CBD, tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.
Pregnancy. It is not known if or how CBD could affect pregnancy or harm a fetus. Some CBD products may be contaminated with THC, the main psychoactive chemical in cannabis. This could cause unwanted effects and side effects for you and your baby. Tell your health care provider if you are pregnant or plan to become pregnant.
Breastfeeding. CBD passes into breast milk. Some CBD products may be contaminated with THC, which also passes into breast milk and can cause harm to your baby. Tell your health care provider if you are breastfeeding or plan to breastfeed.
Interactions
Does CBD interact with foods or drinks?
Food can change the way your body absorbs CBD. When taking CBD by mouth, it is best to always take it the same way, either with or without food.
CBD can increase levels of caffeine in your body. Caffeine is often found in coffee, tea, sodas, and many different supplements. Taking CBD by mouth can increase the effects and side effects of caffeine in your body.
It is unknown if drinking alcohol will affect CBD. But drinking alcohol while you are taking CBD may increase your risk of drowsiness and liver damage. It is best to limit the amount of alcohol you drink.
Does CBD interact with medicines (drug interactions)?
Always tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.
In particular, make sure that you discuss if you are using any of the following before taking CBD by mouth.
- Clobazam (Onfi, Sympazan), which is a medicine used for seizures
- Divalproex sodium, valproate sodium (Depakote and others), or valproic acid, which is a medicine used for seizures and other conditions
- Any other medicine for seizures, such as carbamazepine, phenobarbital, or phenytoin
- Any medicine that causes dizziness and sleepiness, such as prescription pain medicines, sleep medicines, or medicines for anxiety
Many other medicines may alter the blood levels of CBD, and vice versa. Tell your health care provider about all medicines that you take or have recently taken.
The interactions between CBD and medicines are not fully understood. As with most unapproved ingredients, the research on drug interactions with CBD is incomplete. Always check with your health care provider before using CBD with any medicines.
Dosing
What should I do if I accidentally use too much CBD?
If you or someone else has used too much CBD, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.
CBD is available in many different forms, and these products may contain a wide range of doses. Some of these products may also contain other ingredients, including other cannabinoids. Read the product label closely and speak with a health care provider about how to use CBD safely. Do not use double or extra doses, even if you miss a dose.
References
- Drugs and Lactation Database (LactMed) [Internet]: “Cannabidiol.”
- Epidiolex (Jazz Pharmaceuticals) US Prescribing Information, July 2025.
- JAMA: “Cannabidiol and liver enzyme level elevations in healthy adults: a randomized clinical trial.”
- JAMA Patient Page: “Cannabinoid Hyperemesis Syndrome.”
- LiverTox: Clinical and Research Information on Drug-Induced Liver Injury [Internet]: “Cannabidiol.”
- National Cancer Institute: “Cannabis and Cannabinoids (PDQ)–Health Professional Version,” “Cannabis and Cannabinoids (PDQ)–Patient Version.”
- National Center for Complementary and Integrative Health: “Cannabis (Marijuana) and Cannabinoids: What You Need To Know.”
- National Institute on Drug Abuse: “Cannabis (Marijuana).”
- Plants: “Potential of industrial hemp for phytoremediation of heavy metals.”
- Drug Enforcement Administration: “Marijuana/Cannabis Drug Fact Sheet.”
- FDA: “FDA Regulation of Cannabis and Cannabis-Derived Products, Including Cannabidiol (CBD),” “What You Need to Know (And What We’re Working to Find Out) About Products Containing Cannabis or Cannabis-derived Compounds, Including CBD,” “What You Should Know About Using Cannabis, Including CBD, When Pregnant or Breastfeeding.”