Key points
- Cannabis refers to the dried flowers, leaves, stems, and seeds of the cannabis plant.
- Cannabis can be used in a number of ways.
- How cannabis affects a person depends on several factors.
What we know about cannabis
Cannabis, which can also be called marijuana, weed, pot, or bud, refers to the dried flowers, leaves, stems, and seeds of the cannabis plant. The cannabis plant contains more than 100 compounds (or cannabinoids). These compounds include tetrahydrocannabinol (THC), which is impairing or mind-altering, as well as other active compounds, such as cannabidiol (CBD). CBD – by itself - is not impairing, meaning it does not cause a "high".1
Types
Cannabis can be used in a number of ways.
The most common ways include:23
- Smoked in joints (like a cigarette), in blunts (cigars or cigar wrappers that have been partly or completely refilled with cannabis) or in bongs (pipes or water pipes)
- Vaped using electronic vaporizing devices (like vape pens) or other vaporizers
- Mixed or infused into foods or drinks (called edibles) like cookies, cakes, or brownies, or tea, cola, or alcohol
Additionally, some people inhale the oil concentrates and other extracts from the cannabis plant—this is known as dabbing. THC oils and concentrates used in vaping and dabbing often involve using highly concentrated forms of THC and may contain additives or be contaminated with other substances that may be harmful.4
How cannabis affects a person depends on several factors, including:56
- Concentration of THC used
- Frequency of cannabis use
- Use of cannabis with other substances (e.g., alcohol or other drugs), which could increase risk of harm
- Mode of cannabis use (e.g., consuming edibles or products with high THC concentration can have delayed or unpredictable effects and increases the risk of overdose or poisoning)
- Previous experience with cannabis or other drugs
- Biology (e.g., genes, DNA)
- Sex (e.g., women may experience more dizziness after using cannabis compared to men)
Cannabis as medicine
The Food and Drug Administration (FDA) has approved one plant-based cannabis drug called Epidiolex, which contains a purified form of CBD. The prescription medication is approved for treating seizures associated with two rare and severe forms of epilepsy (Lennox-Gastaut syndrome and Dravet syndrome) as well as seizures associated with a rare genetic disorder called tuberous sclerosis complex.
The FDA has also approved two medicines (dronabinol [brand names: Marinol and Syndros] and nabilone [brand name: Cesamet]) that are made from a synthetic or lab-made chemical that mimics THC. These medicines are used to treat nausea in patients with cancer who are having chemotherapy treatment, and to increase appetite in individuals with AIDS who do not feel like eating (wasting syndrome).
These approved products are only available with a prescription from a licensed healthcare provider. There are currently no other FDA-approved uses for cannabis or its derivatives.
- Rosenberg EC, Tsien RW, Whalley BJ, et al. Cannabinoids and epilepsy. Neurotherapeutics. 2015;12(4):747-68.
- Schauer GL, Njai R, Grant-Lenzy AM. Modes of marijuana use – smoking, vaping, eating, and dabbing: Results from the 2016 BRFSS in 12 States. Drug Alcohol Depend. 2020;209:107900. doi: 10.1016/j.drugalcdep.2020.107900.
- Schauer GL, King BA, Bunnell RE, et al. Toking, vaping, and eating for health or fun: Marijuana use patterns in adults, U.S., 2014. Am J Prev Med. 2016;50(1):1-8. doi:10.1016/j.amepre.2015.05.027.
- Raber JC, Elzinga S, Kaplan C. Understanding dabs: Contamination concerns of cannabis concentrates and cannabinoid transfer during the act of dabbing. J Toxicol Sci. 2015;40(6):797–803. doi: 10.2131/jts.40.797.
- National Academies of Sciences Engineering and Medicine. The health effects of cannabis and cannabinoids: Current state of evidence and recommendations for research. Washington, DC: The National Academies Press; 2017. https://nap.nationalacademies.org/catalog/24625/the-health-effects-of-cannabis-and-cannabinoids-the-current-state. Accessed February 8, 2024.
- Fattore L, Fratta W. How important are sex differences in cannabinoid action? Br J Pharmacol. 2010;160(3):544-548. doi: 10.1111/j.1476-5381.2010.00776.x.