Fact Check

Use our interactive tool to look up scientifically supported answers to key questions on cannabinoids and cannabis-based products.

Cannabis is the term used to describe the cannabis plant and its products. The cannabis plant, known as ‘Cannabis sativa L’, is widely used for fibre, food, oil and medicine^1–3
- Learn more about the different parts of the cannabis plant here
Marijuana is a term for cannabis that is often used when talking about recreational use, but can also be used to refer to ‘medical marijuana’ (which is the same as ‘medical cannabis’)^2,4
‘Medical cannabis’ is a broad term used to describe products containing cannabis that are used as a medical treatment (usually available on prescription), but are not approved by government bodies^2,5
CBD oil – CBD stands for cannabidiol, which is a type of molecule found in the cannabis plant known as a ‘phytocannabinoid’.⁶ In CBD oils, the CBD has been taken from the cannabis plant and mixed with an oil.⁷These products are not medicines and their quality is not always guaranteed, meaning they might contain a different amount of CBD than what is written on the packaging.^7–11 They might also contain other phytocannabinoids, including THC (delta-9-tetrahydrocannabinol)^8,11

References: 1. Pertwee. Handbook of Cannabis. Series editor Iversen L. Oxford University Press. Oxford, UK. 2014; 2. Papaseit et al. Int J Med Sci 2018;15:1286–95; 3. Small, Marcus. Trends in new crops and new uses. Editors Janick J., Whipkey A. ASHS Press. 2002; 4. US Drug Enforcement Administration (DEA). Marijuana. https://www.dea.gov/factsheets/marijuana. Accessed February 2022; 5. National Health Service (NHS). Medical cannabis (and cannabis oils). https://www.nhs.uk/conditions/medical-cannabis/. Accessed February 2022; 6. Morales et al. Prog Chem Org Nat Prod 2017;103:103–31; 7. Hazekamp. Med Cannabis Cannabinoids 2018;1:65–72; 8. Liebling et al. Cannabis Cannabinoid Res 2020;DOI:10.1089/can.2019.0078; 9. Bonn-Miller et al. JAMA 2017;318:1708–9; 10. Food and Drug Administration (FDA). What you need to know (and what we’re working to find out) about products containing cannabis or cannabis-derived compounds, including CBD. 2020. https://www.fda.gov/consumers/consumer-updates/what-you-need-know-and-what-were-working-find-out-about-products-containing-cannabis-or-cannabis. Accessed February 2022; 11. Chesney et al. Ther Adv Psychopharmacol 2020;10:1–13.

Cannabinoids are natural or manufactured molecules related to those found in the cannabis plant. There are three types:^1–3
- Phytocannabinoids are made in the cannabis plant. There are over 120 different known phytocannabinoids, of which the best understood are CBD (cannabidiol) and THC (delta-9-tetrahydrocannabinol). Others include CBC (cannabichromene), CBG (cannabigerol), CBN (cannabinol), CBV (cannabivarin), CBDV (cannabidivarin), THCV (delta-9-tetrahydrocannabivarin) and another type of THC (delta-8-tetrahydrocannabinol)¹
- Endocannabinoids are made naturally in the human body. By attaching to targets called ‘cannabinoid receptors’, which are found all over the body and in the brain, they help to control many processes such as mood and hunger^2,4,5
- Synthetic cannabinoids are manufactured chemicals that are designed to look like cannabinoids or attach to cannabinoid receptors. They may be used for lab research, as medicines or recreationally^3,6

References: 1. Morales et al. Prog Chem Org Nat Prod 2017;103:103–31; 2. Cristino et al. Nat Rev Neurol 2020;16:9–29; 3. National Health Service (NHS) UK. Cannabis-based products for medicinal use: frequently asked questions. https://www.england.nhs.uk/medicines-2/support-for-prescribers/cannabis-based-products-for-medicinal-use/cannabis-based-products-for-medicinal-use-frequently-asked-questions/. Accessed February 2022; 4. Stasiulewicz et al. Int J Mol Sci 2020;21:2778; 5. Zou, Kumar. Int J Mol Sci 2018;19:833; 6. VanDolah et al. Mayo Clin Proc 2019;94:1840–51.

Historically, Cannabis sativa and Cannabis indica were considered related versions (or ‘subspecies’) of the cannabis plant^1,2
For decades, they were thought to be very different, producing distinct effects on the human body (though this has never been proven)³
Over time, this understanding has changed, and it is now believed that there is only a single species: ‘Cannabis sativa L’⁴
- Although only one species, there are many varieties of the plant (some used for fibres, e.g. ‘hemp’, and others used for medicines)⁴
The names ‘Cannabis sativa’ and ‘Cannabis indica’ are still used for some cannabis-based products today, but they no longer relate to the different scientific versions (or subspecies) that they used to, and this can be a source of confusion for people who are looking to use these products³

References: 1. Small, Marcus. Trends in new crops and new uses. Editors Janick J., Whipkey A. ASHS Press. 2002; 2. Russo. Chem Biodivers 2007;4:1614–48; 3. Vergara et al. PeerJ 2021;9:e10672; 4. Hurgobin et al. New Phytol 2021;230:73–89.

CBD (cannabidiol) and THC (delta-9-tetrahydrocannabinol) are two of the best understood cannabis molecules made by plants (known as ‘phytocannabinoids’).¹ Although they are found in the same plant, they cause different effects in the body^2–5
As with other phytocannabinoids, THC and CBD are made by the cannabis plant (called Cannabis sativa L)⁴
THC is thought to act by attaching to targets in the human body known as ‘cannabinoid receptors’. By ‘switching on’ a group of these receptors (called ‘CB₁’) in the brain, THC is believed to cause the ‘high’ feeling that is associated with cannabis^4,5
In contrast, CBD does not cause the ‘high’ feeling and is believed to mostly work at places in the body other than the cannabinoid receptors^4,5
While CBD and THC have different ways of working, ongoing studies are helping to improve researchers’ understanding of both of them¹

References: 1. Ladha et al. Molecules 2020;25:4042; 2. National Center for Biotechnology Information. PubChem Compound Summary for CID 644019, Cannabidiol. https://pubchem.ncbi.nlm.nih.gov/compound/Cannabidiol. Accessed February 2022; 3. National Center for Biotechnology Information. PubChem Compound Summary for CID 16078, Dronabinol. https://pubchem.ncbi.nlm.nih.gov/compound/Dronabinol. Accessed February 2022; 4. Morales et al. Prog Chem Org Nat Prod 2017;103:103–31; 5. Ligresti et al. Physiol Rev 2016;96:1593–659.

Whether cannabis-based products are legal or not depends on a number of things, including the type of product, the type of cannabis-related molecule (or ‘cannabinoid’) found in the product, and the country^1–3
- There are many known cannabinoids,⁴ and drug laws apply to some, like THC (delta-9-tetrahydrocannabinol), but not others, like CBD (cannabidiol). This means products that only contain CBD are subject to different rules than those containing THC^1–3,5
- Regulatory approved cannabis-based medicines undergo thorough testing in research studies and are approved for use in specific countries by a government body. They can be obtained by a prescription in countries where they have been approved. Government bodies that approve these types of medicines vary depending on the country you are in – for example, in Europe it might be the European Medicines Agency (or EMA for short), and in the USA it is likely to be the Food and Drug Administration (or FDA for short)^2,5,6
- For ‘medical cannabis’ (or non-regulatory approved cannabis-based products), the legal situation varies depending on the country^1,3,7
- For CBD-containing products and foods (such as oils and supplements), the legal status varies and in some cases is unclear in certain countries^7–10
- The use of recreational cannabis is illegal in most European countries³

References: 1. UK Government. Drug licensing factsheet: Cannabis, CBD and other cannabinoids. https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/825872/factsheet-cannabis-cbd-and-cannabinoids-2019.pdf. Accessed February 2022; 2. European Monitoring Centre for Drugs and Drug Addiction. Medical use of cannabis and cannabinoids: questions and answers for policymaking. December 2018. https://www.emcdda.europa.eu/system/files/publications/10171/20185584_TD0618186ENN_PDF.pdf. Accessed February 2022; 3. European Monitoring Centre for Drugs and Drug Addiction. Cannabis legislation in Europe: an overview, Publications Office of the European Union, Luxembourg. 2017. https://publications.europa.eu/resource/cellar/c0703c01-0d38-11e7-8a35-01aa75ed71a1.0001.03/DOC_1. Accessed February 2022; 4. Morales et al. Prog Chem Org Nat Prod 2017;103:103–31; 5. Food and Drug Administration (FDA). FDA and Cannabis: Research and Drug Approval Process. https://www.fda.gov/news-events/public-health-focus/fda-and-cannabis-research-and-drug-approval-process. Accessed February 2022; 6. European Medicines Agency. European regulatory system for medicines: A consistent approach to medicines regulation across the European Union (EMA/716925/2016). 2016. https://www.scribd.com/document/461348291/european-regulatory-system-medicines-european-medicines-agency-consistent-approach-medicines-en-pdf. Accessed February 2022; 7. Food and Drug Administration (FDA). FDA regulation of cannabis and cannabis-derived products, including cannabidiol (CBD). 2020. https://www.fda.gov/news-events/public-health-focus/fda-regulation-cannabis-and-cannabis-derived-products-including-cannabidiol-cbd. Accessed February 2022; 8. European Monitoring Centre for Drugs and Drug Addiction. Italy and Sweden: court decisions on low-THC cannabis products. 2019. https://www.emcdda.europa.eu/news/2019/italy-and-sweden-court-decisions-low-thc-cannabis-products_en. Accessed February 2022; 9. UK Food Standards Agency. Consumer advice on cannabidiol extracts. 2020. https://www.food.gov.uk/safety-hygiene/cannabidiol-cbd. Accessed February 2022; 10. Australian Government Department of Health Therapeutic Goods Administration. Notice of interim decisions to amend (or not amend) the current Poisons Standard. 2020. https://www.tga.gov.au/sites/default/files/notice-interim-decisions-proposed-amendments-poisons-standard-acms-and-joint-acms-accs-meetings-june-2020.pdf. Accessed February 2022.

Our understanding of cannabis and cannabis-related molecules (or ‘cannabinoids’) is continuing to grow.¹ However, up until now, only a few medical uses have been thoroughly tested in research studies involving patients^2,3
While there is a lot of interest in cannabis as a possible ‘cure’ for conditions,⁴ it is important to distinguish between treating a condition to help with symptom relief and treating to ‘cure’ the condition. Cannabis-based products have not yet been proven to ‘cure’ any condition^5,6
For cannabis-based products that have been approved as medicines by government bodies (such as the United States Food and Drug Administration [FDA] and the European Medicines Agency [EMA]), their use in helping to treat (but not cure) certain conditions is supported by evidence^5,7

References: 1. Montero-Oleas et al. BMC Complement Med Ther 2020;20:12; 2. Stasiulewicz et al. Int J Mol Sci 2020;21:2778; 3. Whiting et al. JAMA 2015;313:2456–73; 4. Shi et al. Cureus 2019;11:e3918; 5. European Monitoring Centre for Drugs and Drug Addiction. Medical use of cannabis and cannabinoids: questions and answers for policymaking. 2018. https://www.emcdda.europa.eu/system/files/publications/10171/20185584_TD0618186ENN_PDF.pdf. Accessed February 2022; 6. Turner, Agrawal. Marijuana. Treasure Island (FL): StatPearls Publishing. 2020; 7. Food and Drug Administration (FDA). FDA regulation of cannabis and cannabis-derived products, including cannabidiol (CBD). 2020. https://www.fda.gov/news-events/public-health-focus/fda-regulation-cannabis-and-cannabis-derived-products-including-cannabidiol-cbd. Accessed February 2022.

Of the 120+ known cannabis-related molecules (or ‘cannabinoids’), only a small number are thought to cause the 'high' feeling associated with using cannabis^1,2
The ‘high’ feeling is brought about when cannabinoids attach to, and ‘switch on’, a specific type of target found in the brain (a cannabinoid receptor known as ‘CB₁’).^1–3 Examples of cannabinoids that cause the feeling of being ‘high’ include THC (delta-9-tetrahydrocannabinol) and CBN (cannabinol).² The extent of the ‘high’ caused by these cannabinoids depends on how the product is taken and how much of it gets into the body^4,5
Other cannabinoids, including CBD (cannabidiol), CBC (cannabichromene) and CBV (cannabidivarin), do not ‘switch on’ the CB₁ receptor and so are not linked with the feeling of being ‘high’.⁶ However, these may cause other effects, such as drowsiness^7,8

References: 1. Pertwee. Handbook of Cannabis. Series editor Iversen L. Oxford University Press. Oxford, UK. 2014; 2. Morales et al. Prog Chem Org Nat Prod 2017;103:103–31; 3. Iversen. Brain 2003; 126: 1252–70; 4. Heustis. Chem Biodivers 2007;4:1770–804; 5. Spindle et al. JAMA Netw Open 2018;1:e184841; 6. Ligestri et al. Physiol Rev 2016;96:1593–659; 7. Chesney et al. Ther Adv Psychopharmacol 2020;10:1–13; 8. Brown, Winterstein. J Clin Med 2019;8:989.

‘Evidence’ is the information gathered from studies that shows how well a medicine or product works and what side effects it may cause. Evidence can vary in quality and it is therefore important to ask the right questions about the evidence supporting any information you may read or hear about¹
The use of cannabis-based medicines (i.e. medicines that have been approved by government bodies such as the United States Food and Drug Administration [FDA] and the European Medicines Agency [EMA]) is supported by high-quality evidence.^2,3However, this is not the case for all cannabis-based products. For example, the medical use of CBD-containing products sold over the counter is not supported by high-quality evidence^4,5

References: 1. Szajewska. Ann Nutr Metab 2018;72(Suppl 3):13–23; 2. European Monitoring Centre for Drugs and Drug Addiction. Medical use of cannabis and cannabinoids: questions and answers for policymaking. 2018. https://www.emcdda.europa.eu/publications/rapid-communications/medical-use-of-cannabis-and-cannabinoids-questions-and-answers-for-policymaking_en. Accessed February 2022; 3. Food and Drug Administration (FDA). FDA regulation of cannabis and cannabis-derived products, including cannabidiol (CBD). 2020. https://www.fda.gov/news-events/public-health-focus/fda-regulation-cannabis-and-cannabis-derived-products-including-cannabidiol-cbd. Accessed February 2022; 4. Hazekamp. Med Cannabis Cannabinoids 2018;1:65–72; 5. Food and Drug Administration (FDA). What you need to know (and what we’re working to find out) about products containing cannabis or cannabis-derived compounds, including CBD. 2020. https://www.fda.gov/consumers/consumer-updates/what-you-need-know-and-what-were-working-find-out-about-products-containing-cannabis-or-cannabis. Accessed February 2022.

There are many different types of products that are made from cannabis or that include cannabis-related molecules (known as ‘cannabinoids’) and it is important to be aware of any risks or safety concerns that might exist^1–4
When thinking about recreational cannabis, there are both short-term and long-term risks or side effects associated with its use. Short-term side effects include anxiety and loss of memory,^5,6 while long-term side effects include those affecting the brain, heart and lungs^4,6
- Recreational cannabis is also linked with risk of addiction.⁷ In fact, one study found that 9% of people who used recreational cannabis became addicted⁸
- The strength of recreational cannabis has increased since the 1970s. This is because cannabis plants that are grown for recreational use now contain higher levels of THC (delta-9-tetrahydrocannabinol), a specific molecule made by the cannabis plant (or ‘phytocannabinoid’) that causes the feeling of being ‘high’⁹
Aside from recreational cannabis, other cannabis-based products are not without risk^1–3

References: 1. Whiting et al. JAMA 2015;313:2456–73; 2. Pratt et al. Syst Rev 2019;8:320; 3. Ladha et al. Molecules 2020;25:4042; 4. Bonomo et al. Br J Clin Pharmacol 2018;84:2495–8; 5. Hindley et al. Lancet Psychiatry 2020;7:344–53; 6. World Health Organization (WHO). The health and social effects of nonmedical cannabis use. 2016. https://www.who.int/substance_abuse/publications/msbcannabis.pdf. Accessed February 2022; 7. Volkow et al. N Engl J Med 2014;370:2219–27; 8. Lopez-Quintero et al. Drug Alcohol Depend 2011;115:120–30; 9. Chandra et al. Eur Arch Psychiatry Clin Neurosci 2019;269:5–15.

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Fact Check

What is meant by cannabis, marijuana, medical cannabis, and CBD oil?

What are cannabinoids?

What is the difference between Cannabis sativa and Cannabis indica?

What is the difference between CBD and THC?

What is the legal status of cannabis-based products?

What evidence is behind the use of cannabis-based products in helping to treat or cure conditions?

How does cannabis make people feel ‘high’?

Is the use of different cannabis-based medicines and products always supported by evidence?

What are the risks or safety concerns associated with cannabis?