What is CBD oil and is it safe to use?
What is CBD oil, is it legal in the UK and what are the benefits and risks of using it? We asked a dietitian to take a closer look at this food supplement.
CBD oil is increasingly popular, both as a food supplement and as an oil to apply topically to the skin. We asked dietitian Emer Delaney to explain what it is, why people use it and whether it’s safe.
What is CBD oil?
Cannabidiol (CBD) is a cannabinoid – a chemical compound that acts throughout the body, including on certain parts of the brain, and is becoming increasingly popular in the health world. It comes from the cannabis plant; however, unlike its counterpart, tetrahydrocannabinol (THC), which is responsible for the ‘high’ from marijuana, CBD, derived from the hemp plant, is non-intoxicating and some believe it may have potential health and wellness benefits. Once extracted from the cannabis plant, it is diluted with a carrier such as olive or coconut oil – this improves its bio-availability.
Is CBD oil legal in the UK?
Contrary to popular belief, CBD oil is legal in the UK as it is not a controlled substance. There are, however, strict restrictions over its THC content. CBD oil that isn’t medically prescribed can only have a maximum THC content of 0.2%. CBD oil products that have a higher THC content may be available to buy online, but not legally
A small number of patients in the UK may be prescribed a cannabis-based medicine to treat epilepsy or nausea during chemotherapy. Visit the NHS website for more information on medical cannabis.
It’s worth noting that there are no CBD products authorised for use in animals in the UK. If you are considering CBD oil for your pet, only a vet can prescribe a legal human CBD product.
What is CBD oil used for?
Supporters of CBD oil believe it may help a number of clinical conditions, including refractory epilepsy, chronic pain, depression, anxiety and acne. However, further robust evidence is required as much of the research is carried out on animal models.
A systematic review looking at the use of CBD for epilepsy concluded that there is insufficient evidence to support the efficacy and long-term safety of using it to treat epilepsy. It does, however, suggest that, albeit in very low numbers, small daily doses were safe in a small group of adults for a short period of time.
There are some suggestions from animal studies that CBD may be beneficial for osteoarthritis, through topical application for inflammation or joint pain, however, it has been difficult to attribute the therapeutic benefits to CBT alone.
One study reported reduced pain and muscle spasms in people with multiple sclerosis.
Early evidence looking into the use of CBD in the treatment of anxiety and depression has found some exciting results – although on very small samples. The first study assessed anxiety links with public speaking; it found a very specific dose of CBD (300mg) showed anti-anxiety effects. The second study was a stand-alone case report of one child with post-traumatic stress disorder (PTSD). It found CBD oil helped the child safely reduce her anxiety and improve sleep.
CBD may also have the potential to help reduce acne; however, it is important to note that this research is still in its infancy.
For all the above uses, more human studies are needed before conclusive results may be drawn.
Can I buy CBD oil safely?
Most large health food stores will stock ‘pure’ CBD oil. However, as it is classed as a ‘food supplement’ rather than a ‘medicinal product’, it isn’t regulated in the UK. This means you cannot know for sure that the product you buy contains the ‘active’ ingredients at the amounts listed on the label. Furthermore, the product may contain contaminants such as pesticides, heavy metals and other elements. For this reason, the NHS highlights there is no guarantee that these products will be of good quality or provide the intended health benefits.
Is CBD oil safe for everyone?
If you’re considering using CBD oil, you should speak to your GP or other healthcare professional to ensure that it is safe and appropriate for you to do so.
This is particularly important if you are experiencing any concerning symptoms, if you have any pre-existing conditions or if you are taking any medication including statins, blood-thinning medication and calcium channel blockers.
Although the use of CBD is controversial, it does seem to be tolerated by most people. It has, however, caused hypotension and light-headedness in a small number of patients. As it does not contain the THC part of the cannabis plant, the oil will not induce a ‘high’.
CBD oil should not be used by pregnant or breastfeeding women.
This article was reviewed on 21 March 2022 by Kerry Torrens.
Kerry Torrens BSc. (Hons) PgCert MBANT is a registered nutritionist with a post-graduate diploma in Personalised Nutrition & Nutritional Therapy. She is a member of the British Association for Nutrition and Lifestyle Medicine (BANT) and a member of the Guild of Food Writers. Over the last 15 years she has been a contributing author to a number of nutritional and cookery publications including BBC Good Food.
All health content on bbcgoodfood.com is provided for general information only, and should not be treated as a substitute for the medical advice of your own doctor or any other health care professional. If you have any concerns about your general health, you should contact your local health care provider. See our website terms and conditions for more information.
Have you tried CBD oil and if so, did you find it beneficial? Let us know in the comments below.
The Potential Side Effects of CBD
Wendy Rose Gould is a lifestyle reporter with over a decade of experience covering health and wellness topics.
Verywell Mind articles are reviewed by board-certified physicians and mental healthcare professionals. 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.
Steven Gans, MD is board-certified in psychiatry and is an active supervisor, teacher, and mentor at Massachusetts General Hospital.
Verywell Mind content is rigorously reviewed by a team of qualified and experienced fact checkers. Fact checkers review articles for factual accuracy, relevance, and timeliness. We rely on the most current and reputable sources, which are cited in the text and listed at the bottom of each article. Content is fact checked after it has been edited and before publication. Learn more.
Karen Cilli is a fact-checker for Verywell Mind. She has an extensive background in research, with 33 years of experience as a reference librarian and educator.
Verywell / Alex Dos Diaz
Generally speaking, CBD is considered a safe substance when applied topically or taken orally. There are, however, some potential side effects to keep in mind when using this substance, the majority of which are mild.
Common Side Effects of CBD
The most comment side effects of CBD include drowsiness, gastrointestinal issues, dry mouth, reduced appetite, nausea, and interaction with other medications. Those are outlined in detail below.
Some common side effects when using CBD include drowsiness and sedation. This is also considered a benefit, but Dr. Jas Matharu-Daley, a physician and chief medical officer for a CBD brand, notes that the effects might be too strong if you’re also taking CBD with other sedating medications.
Some people may get diarrhea or liver problems [when using CBD]. This is dependent on the individual and their medical history, so monitoring is important,” says Dr. Matharu-Daley.
Also known as “cotton mouth,” CBD can potentially cause your mouth and eyes to feel very dry. Though this side effect is more likely to occur with THC, it can happen with CBD as well.
Can Interact With Other Medications
CBD might interfere with the other medications you take. Dr. Matharu-Daley says it’s important to talk to your doctor about whether CBD could affect your existing prescriptions.
In some cases, those who ingest CBD supplements might experience nausea, says Dr. Matharu-Daley. This depends on how sensitive the person is to CBD, as well as the amount they ingest.
Because CBD supplements come in so many different forms—such as oils, gummies, tinctures, and vapors—the amount that’s actually absorbed can vary drastically. This, combined with each person, will ultimately affect which (if any) CBD side effects you might experience.
What Is Cannabidiol (CBD)?
CBD—the abbreviation for cannabidiol, a substance that’s generally derived from the hemp plant—has skyrocketed in popularity over the last five years. In fact, according to research, “CBD” as a Google search term remained stable from 2004 to 2014 but has since ballooned by up to 605%.
CBD is one of the many chemical compounds that is found in the cannabis plant—referred to as cannabis sativa. There are two primary parts of the plant that humans use. One is THC, or Delta-9-Tetrahydrocannabinol, and the other is CBD. Though they’re from the same plant, THC and CBD are quite different from each other.
“CBD is not an intoxicating substance, whereas THC is a psychoactive that can get you high,” explains Dr. Jas Matharu-Daley, a physician and consultant for a brand that specializes in CBD production.
Are There Any Benefits Associated With Using CBD?
There are several reasons why someone might want to use CBD. The substance can be found in a multitude of products ranging from pain-relieving creams to edible tinctures to skincare. Research is still underway, but over the last few decades scientists have become more aware of how CBD might be beneficial when applied either topically or ingested.
“Since discovering the endocannabinoid system (ECS) in the body in the 1990s, CBD has been researched more extensively. The ECS is a central regulatory system restoring normal balance and homeostasis in a range of human physiologic systems throughout the body and brain and has cannabinoid receptors and chemicals in its function,” explains Dr. Matharu-Daley.
CBD benefits include the following:
- CBD can have positive impact on the brain. In fact, Dr. Matharu-Daley says that the substance is legally prescribed in a specific medication for certain severe forms of epilepsy in children.
- It has also been shown to have anti-inflammatory properties, which is why you often see CBD in topical products such as oils, creams, and lotions.
- Some research points to CBD’s ability to relieve stress and anxiety.
- It has been used as a nausea treatment in some countries.
- CBD may potentially reduce pain symptoms.
- It has antioxidant properties, which means it can help fight off free radical damages that leads to premature aging.
- Regarding skincare, CBD may help reduce excessive oil production in those with very oily skin types.
Ultimately, the primary reasons why people use CBD is because it tends to have calming, relaxing, pain-reducing effects. It has been used to alleviate joint pain and nerve pain, reduce anxiety and stress, treat insomnia, improve migraines, and address nausea.
CBD Is Still an Unregulated Substance
It’s important to point out that CBD is not regulated by the FDA and therefore dosages might not be accurate. It’s also difficult to know what an appropriate dose is the first time you try a new product.
“If the CBD is from a reputable source and one that has been inspected by a third-party independent lab, the content of CBD is more reliable,” notes Dr. Matharu-Daley. “The CBD should be organically grown, free of pesticides and heavy metals, and not sourced in food which can affect absorption. Generally, CBD is safe and side effects are few at low doses.”
A Word From Verywell
CBD is technically an unregulated substance in the United States and therefore it ought to be used with caution. This is especially important for those taking additional medications and/or those with ongoing medical issues. That said, preliminary research on CBD and its benefits are promising in relation to helping with mild to moderate health concerns and it is generally considered a safe substance. Health professionals do not consider CBD a cure-all for serious medical issues, including cancer.
As with any sort of supplement, we recommend speaking to your medical doctor about whether using CBD makes sense for you. Your doctor can also recommend certain products that align with your needs and help ensure you get the correct dosage.
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.