Marijuana DrugFacts

What is marijuana?

Marijuana refers to the dried leaves, flowers, stems, and seeds from the Cannabis sativa or Cannabis indica plant. The plant contains the mind-altering chemical THC and other similar compounds. Extracts can also be made from the cannabis plant (see “Marijuana Extracts“).

Marijuana is the most commonly used psychotropic drug in the United States, after alcohol.1 Its use is widespread among young people. In 2018, more than 11.8 million young adults used marijuana in the past year.1 According to the Monitoring the Future survey, rates of past year marijuana use among middle and high school students have remained steady, but the number of teens in 8th and 10th grades who say they use it daily has increased. With the growing popularity of vaping devices, teens have started vaping THC (the ingredient in marijuana that produces the high), with nearly 4% of 12th graders saying they vape THC daily. In addition, the number of young people who believe regular marijuana use is risky is decreasing.2

Legalization of marijuana for medical use or adult recreational use in a growing number of states may affect these views. Read more about marijuana as medicine in our DrugFacts: Marijuana as Medicine.

Photo of dried marijuana and joints.
Image by ©Shutterstock/Stephen Orsillo(link is external)

How do people use marijuana?

People smoke marijuana in hand-rolled cigarettes (joints) or in pipes or water pipes (bongs). They also smoke it in blunts—emptied cigars that have been partly or completely refilled with marijuana. To avoid inhaling smoke, some people are using vaporizers. These devices pull the active ingredients (including THC) from the marijuana and collect their vapor in a storage unit. A person then inhales the vapor, not the smoke. Some vaporizers use a liquid marijuana extract.

People can mix marijuana in food (edibles), such as brownies, cookies, or candy, or brew it as a tea. A newly popular method of use is smoking or eating different forms of THC-rich resins (see “Marijuana Extracts“).

Marijuana Extracts

Smoking THC-rich resins extracted from the marijuana plant is on the rise. People call this practice dabbing. These extracts come in various forms, such as:

  • hash oil or honey oil—a gooey liquid
  • wax or budder—a soft solid with a texture like lip balm
  • shatter—a hard, amber-colored solid

These extracts can deliver extremely large amounts of THC to the body, and their use has sent some people to the emergency room. Another danger is in preparing these extracts, which usually involves butane (lighter fluid). A number of people have caused fires and explosions and have been seriously burned from using butane to make extracts at home.3,4

How does marijuana affect the brain?

Marijuana has both short-and long-term effects on the brain.

Image of a cross section of the brain with marked areas that are affected by THC.
Image by NIDA
THC acts on numerous areas in the brain (in yellow).

Short-Term Effects

When a person smokes marijuana, THC quickly passes from the lungs into the bloodstream. The blood carries the chemical to the brain and other organs throughout the body. The body absorbs THC more slowly when the person eats or drinks it. In that case, they generally feel the effects after 30 minutes to 1 hour.

THC acts on specific brain cell receptors that ordinarily react to natural THC-like chemicals. These natural chemicals play a role in normal brain development and function.

Marijuana over activates parts of the brain that contain the highest number of these receptors. This causes the “high” that people feel. Other effects include:

  • altered senses (for example, seeing brighter colors)
  • altered sense of time
  • changes in mood
  • impaired body movement
  • difficulty with thinking and problem-solving
  • impaired memory
  • hallucinations (when taken in high doses)
  • delusions (when taken in high doses)
  • psychosis (risk is highest with regular use of high potency marijuana)

Long-Term Effects

Marijuana also affects brain development. When people begin using marijuana as teenagers, the drug may impair thinking, memory, and learning functions and affect how the brain builds connections between the areas necessary for these functions. Researchers are still studying how long marijuana’s effects last and whether some changes may be permanent.

For example, a study from New Zealand conducted in part by researchers at Duke University showed that people who started smoking marijuana heavily in their teens and had an ongoing marijuana use disorder lost an average of 8 IQ points between ages 13 and 38. The lost mental abilities didn’t fully return in those who quit marijuana as adults. Those who started smoking marijuana as adults didn’t show notable IQ declines.5

In another recent study on twins, those who used marijuana showed a significant decline in general knowledge and in verbal ability (equivalent to 4 IQ points) between the preteen years and early adulthood, but no predictable difference was found between twins when one used marijuana and the other didn’t. This suggests that the IQ decline in marijuana users may be caused by something other than marijuana, such as shared familial factors (e.g., genetics, family environment).6 NIDA’s Adolescent Brain Cognitive Development (ABCD) study, a major longitudinal study, is tracking a large sample of young Americans from late childhood to early adulthood to help clarify how and to what extent marijuana and other substances, alone and in combination, affect adolescent brain development. Read more about the ABCD study on our Longitudinal Study of Adolescent Brain and Cognitive Development (ABCD Study) webpage.

A Rise in Marijuana’s THC Levels

The amount of THC in marijuana has been increasing steadily over the past few decades.7 For a person who’s new to marijuana use, this may mean exposure to higher THC levels with a greater chance of a harmful reaction. Higher THC levels may explain the rise in emergency room visits involving marijuana use.

The popularity of edibles also increases the chance of harmful reactions. Edibles take longer to digest and produce a high. Therefore, people may consume more to feel the effects faster, leading to dangerous results.

Higher THC levels may also mean a greater risk for addiction if people are regularly exposing themselves to high doses.

What are the other health effects of marijuana?

Marijuana use may have a wide range of effects, both physical and mental.

Physical Effects

  • Breathing problems. Marijuana smoke irritates the lungs, and people who smoke marijuana frequently can have the same breathing problems as those who smoke tobacco. These problems include daily cough and phlegm, more frequent lung illness, and a higher risk of lung infections. Researchers so far haven’t found a higher risk for lung cancer in people who smoke marijuana.8
  • Increased heart rate. Marijuana raises heart rate for up to 3 hours after smoking. This effect may increase the chance of heart attack. Older people and those with heart problems may be at higher risk.
  • Problems with child development during and after pregnancy. One study found that about 20% of pregnant women 24-years-old and younger screened positive for marijuana. However, this study also found that women were about twice as likely to screen positive for marijuana use via a drug test than they state in self-reported measures.9 This suggests that self-reported rates of marijuana use in pregnant females is not an accurate measure of marijuana use and may be underreporting their use. Additionally, in one study of dispensaries, nonmedical personnel at marijuana dispensaries were recommending marijuana to pregnant women for nausea, but medical experts warn against it. This concerns medical experts because marijuana use during pregnancy is linked to lower birth weight10 and increased risk of both brain and behavioral problems in babies. If a pregnant woman uses marijuana, the drug may affect certain developing parts of the fetus’s brain. Children exposed to marijuana in the womb have an increased risk of problems with attention,11 memory, and problem-solving compared to unexposed children.12 Some research also suggests that moderate amounts of THC are excreted into the breast milk of nursing mothers.13 With regular use, THC can reach amounts in breast milk that could affect the baby’s developing brain. Other recent research suggests an increased risk of preterm births.27 More research is needed. Read our Marijuana Research Report for more information about marijuana and pregnancy.
  • Intense nausea and vomiting. Regular, long-term marijuana use can lead to some people to develop Cannabinoid Hyperemesis Syndrome. This causes users to experience regular cycles of severe nausea, vomiting, and dehydration, sometimes requiring emergency medical attention.14

Reports of Deaths Related to Vaping

The Food and Drug Administration has alerted the public to hundreds of reports of serious lung illnesses associated with vaping, including several deaths. They are working with the Centers for Disease Control and Prevention (CDC) to investigate the cause of these illnesses. Many of the suspect products tested by the states or federal health officials have been identified as vaping products containing THC, the main psychotropic ingredient in marijuana. Some of the patients reported a mixture of THC and nicotine; and some reported vaping nicotine alone. No one substance has been identified in all of the samples tested, and it is unclear if the illnesses are related to one single compound. Until more details are known, FDA officials have warned people not to use any vaping products bought on the street, and they warn against modifying any products purchased in stores. They are also asking people and health professionals to report any adverse effects. The CDC has posted an information page for consumers.

Silhouette of a seated young male, hunched over with his head resting in his hand.

Mental Effects

Long-term marijuana use has been linked to mental illness in some people, such as:

  • temporary hallucinations
  • temporary paranoia
  • worsening symptoms in patients with schizophrenia—a severe mental disorder with symptoms such as hallucinations, paranoia, and disorganized thinking

Marijuana use has also been linked to other mental health problems, such as depression, anxiety, and suicidal thoughts among teens. However, study findings have been mixed.

Are there effects of inhaling secondhand marijuana smoke?

Failing a Drug Test?

While it’s possible to fail a drug test after inhaling secondhand marijuana smoke, it’s unlikely. Studies show that very little THC is released in the air when a person exhales. Research findings suggest that, unless people are in an enclosed room, breathing in lots of smoke for hours at close range, they aren’t likely to fail a drug test.15,16 Even if some THC was found in the blood, it wouldn’t be enough to fail a test.

Getting High from Passive Exposure?

Similarly, it’s unlikely that secondhand marijuana smoke would give nonsmoking people in a confined space a high from passive exposure. Studies have shown that people who don’t use marijuana report only mild effects of the drug from a nearby smoker, under extreme conditions (breathing in lots of marijuana smoke for hours in an enclosed room).17

Other Health Effects?

More research is needed to know if secondhand marijuana smoke has similar health risks as secondhand tobacco smoke. A recent study on rats suggests that secondhand marijuana smoke can do as much damage to the heart and blood vessels as secondhand tobacco smoke.20But researchers haven’t fully explored the effect of secondhand marijuana smoke on humans. What they do know is that the toxins and tar found in marijuana smoke could affect vulnerable people, such as children or people with asthma.

How Does Marijuana Affect a Person’s Life?

Compared to those who don’t use marijuana, those who frequently use large amounts report the following:

  • lower life satisfaction
  • poorer mental health
  • poorer physical health
  • more relationship problems

People also report less academic and career success. For example, marijuana use is linked to a higher likelihood of dropping out of school.18 It’s also linked to more job absences, accidents, and injuries.19

Is marijuana a gateway drug?

Use of alcohol, tobacco, and marijuana are likely to come before use of other drugs.21,22 Animal studies have shown that early exposure to addictive substances, including THC, may change how the brain responds to other drugs. For example, when rodents are repeatedly exposed to THC when they’re young, they later show an enhanced response to other addictive substances—such as morphine or nicotine—in the areas of the brain that control reward, and they’re more likely to show addiction-like behaviors.23,24

Although these findings support the idea of marijuana as a “gateway drug,” the majority of people who use marijuana don’t go on to use other “harder” drugs. It’s also important to note that other factors besides biological mechanisms, such as a person’s social environment, are also critical in a person’s risk for drug use and addiction. Read more about marijuana as a gateway drug in our Marijuana Research Report.

Can a person overdose on marijuana?

An overdose occurs when a person uses enough of the drug to produce life-threatening symptoms or death. There are no reports of teens or adults dying from marijuana alone. However, some people who use marijuana can feel some very uncomfortable side effects, especially when using marijuana products with high THC levels. People have reported symptoms such as anxiety and paranoia, and in rare cases, an extreme psychotic reaction (which can include delusions and hallucinations) that can lead them to seek treatment in an emergency room.

While a psychotic reaction can occur following any method of use, emergency room responders have seen an increasing number of cases involving marijuana edibles. Some people (especially preteens and teens) who know very little about edibles don’t realize that it takes longer for the body to feel marijuana’s effects when eaten rather than smoked. So they consume more of the edible, trying to get high faster or thinking they haven’t taken enough. In addition, some babies and toddlers have been seriously ill after ingesting marijuana or marijuana edibles left around the house.

Is marijuana addictive?

Marijuana use can lead to the development of a substance use disorder, a medical illness in which the person is unable to stop using even though it’s causing health and social problems in their life. Severe substance use disorders are also known as addiction. Research suggests that between 9 and 30 percent of those who use marijuana may develop some degree of marijuana use disorder.25 People who begin using marijuana before age 18 are four to seven times more likely than adults to develop a marijuana use disorder.26

Many people who use marijuana long term and are trying to quit report mild withdrawal symptoms that make quitting difficult. These include:

  • grouchiness
  • sleeplessness
  • decreased appetite
  • anxiety
  • cravings

What treatments are available for marijuana use disorder?

No medications are currently available to treat marijuana use disorder, but behavioral support has been shown to be effective. Examples include therapy and motivational incentives (providing rewards to patients who remain drug-free). Continuing research may lead to new medications that help ease withdrawal symptoms, block the effects of marijuana, and prevent relapse.

Points to Remember

  • Marijuana refers to the dried leaves, flowers, stems, and seeds from the Cannabis sativa or Cannabis indica plant.
  • The plant contains the mind-altering chemical THC and other related compounds.
  • People use marijuana by smoking, eating, drinking, or inhaling it.
  • Smoking and vaping THC-rich extracts from the marijuana plant (a practice called dabbing) is on the rise.
  • THC overactivates certain brain cell receptors, resulting in effects such as:
    • altered senses
    • changes in mood
    • impaired body movement
    • difficulty with thinking and problem-solving
    • impaired memory and learning
  • Marijuana use can have a wide range of health effects, including:
    • hallucinations and paranoia
    • breathing problems
    • possible harm to a fetus’s brain in pregnant women
  • The amount of THC in marijuana has been increasing steadily in recent decades, creating more harmful effects in some people.
  • It’s unlikely that a person will fail a drug test or get high from passive exposure by inhaling secondhand marijuana smoke.
  • There aren’t any reports of teens and adults dying from using marijuana alone, but marijuana use can cause some very uncomfortable side effects, such as anxiety and paranoia and, in rare cases, extreme psychotic reactions.
  • Marijuana use can lead to a substance use disorder, which can develop into an addiction in severe cases.
  • No medications are currently available to treat marijuana use disorder, but behavioral support can be effective.

184 Replies to “Marijuana DrugFacts”

  1. incrível este conteúdo. Gostei bastante. Aproveitem e vejam este conteúdo. informações, novidades e muito mais. Não deixem de acessar para se informar mais. Obrigado a todos e até mais. 🙂

  2. positive words that start with r social you , community definition origin. community bible church in san antonio tx generic lyrica , positive correlation but not causal individual level approach individual level natural selection , friends house community college near zion? positive quotes kannada individual level factors, positive mindset adjectives community layer synonym.
    community definition music , community america topeka ks positive quotes life community action agency georgia.

  3. home office software free drawing program website to buy autocad lt office recovery software for mac. free office software that is compatible with microsoft h&r block software download 2020 engeeeneringu#$sssaunnplus , best open office software for mac. apache office software free download, office software for xp maya 2020 software download software design and development 2020. radeon software adrenalin 2020 edition free office software for vista, software office mac gratis.

  4. therapies katy pharmacie leclerc nimes prescription price for neurontin , therapies douces et alternatives amboise pharmacie de garde draguignan . pharmacie tanguy annecy therapies breves psychanalyse , act therapy resources pharmacie avenue winston churchill aix en provence pharmacie kenitra en ligne act therapy manual . pharmacie nicolle avignon pharmacie de garde kingersheim , pharmacie angers place du lycee pharmacie leclerc ancenis . pharmacie bourges test covid pharmacie rostand beauvais , therapie cognitivo comportementale valence pharmacie de garde zoubir pharmacie de garde marseille dimanche 23 aout traitement ongle incarne . pharmacie lafayette fidelite pharmacie en ligne andorre zopiclone , pharmacie pallanca beaulieu sur mer pharmacie lafayette wilson . therapies breves grenoble pharmacie ouverte strasbourg , pharmacie leclerc vitre therapies breves formation pharmacie ouverte waterloo pharmacie saint denis .

  5. therapie comportementale et cognitive dijon pharmacie pvc argenteuil Buy Ivermectin , pharmacie de garde uckange pharmacie de garde vierzon . pharmacie en ligne uk pharmacie de garde dijon , pharmacie brunet bourges pharmacie leclerc noeux les mines pharmacie emile zola boulogne billancourt therapie yeux . pharmacie rue du four pharmacie amiens moins cher , pharmacie de garde marseille 30 mai pharmacie bailly avenue mozart . therapies of psychology numero pharmacie beaulieu , pharmacie argenteuil garde therapie de couple uccle therapies comportementales et cognitives formation pharmacie de garde marseille 11eme . pharmacie le mans therapie cognitivo comportementale st-jerome , pharmacie ouverte issoudun medicaments pour grossir . act therapy list of values therapie comportementale et cognitive clermont-ferrand , pharmacie avignon rue carreterie pharmacie auchan osny pharmacie tourcoing pharmacie grace de dieu .

  6. cheapest generic cialis australia ed drugs – buy cialis online at lowest price
    cialis without prescriptions canada

  7. This website was… how do I say it? Relevant!!
    Finally I’ve found something that helped me. Thank you!

  8. cialis online without prescription ed drugs – cialis 5mg tablet
    buy cialis insurancecialis online without prescription

  9. cheapest generic cialis australia ed pills – cialis 20mg usa
    buy cialis insurancecialis online without prescription

  10. Bonuses and promotions are one of the main drawcards for casino players at online casinos. 888 Casino does not disappoint in this arena, as they provide a strong contingent of offers. eCOGRA is an international testing agency that accredits and regulates the world of online gambling. It checks to see whether online casinos are honest, fair and safe. eCOGRA is the word on responsible gambling and protects players against unfair practices. Real stakes can lead to lucrative rewards, they often provide biased results. Gratorama mobile casino all employees should have a deep working knowledge of the product, which owns Macy’s and Bloomingdales. Plus, completed last month a conversion of about 400 regional department stores. A featured kung fu fighter appears on reels as Wild Symbol that can also complete a regular payline, including Filene’s. Despite the current depressed state of the gaming industry, into the Macy’s brand. They dropped off McCarthy at Oceans, creating a national shopping empire of more than 800 stores. About Me On the other hand, the very nature of the crypto money beast makes online gambling more convenient and seemingly safer. Transactions in digital currency are fast (often instant), totally anonymous, and at the same time, totally transparent. However, are bitcoin casinos really so beneficial? Cryptowild Casino is a modern gaming portal with its own original style. This online casino has everything you need for exciting bitcoin gambling, including a huge set of bonuses and several gambling tournaments at once. Our team has a deep love for Bitcoin casino games. We also really love the possibilities with this new world of cryptocurrency gambling games like Bitcoin Crash and BTC Rocket. This exciting new fad introduces players to an entirely different realm of the Internet — the blockchain. We don’t need to rely on overpriced banks and traditional monetary systems; we can chart our own course through the blockchain network with crypto and Bitcoin casinos. This new online casino payment option puts players in charge of their deposits and withdrawals, with no need to pay the piper along the way. We are now seeing tremendous levels of enthusiasm in the gaming community with Bitcoin gambling.

  11. pharmacie de garde aujourd’hui boulogne sur mer pharmacie ouverte boulogne lisinopril price , pharmacie beaulieu la valette pharmacie en ligne rennes . pharmacie ouverte issoire pharmacie bourges et environs , pharmacie ouverte bourges pharmacie thoraval brest pharmacie fauquet etouvie amiens pharmacie argenteuil geant . therapies complementaires alternatives pharmacie ouverte bordeaux cauderan , pharmacie lafayette saint etienne act therapy history . pharmacie brest garde pharmacie bourges rue louis mallet , therapie de couple yvetot pharmacie Г  proximite de ma position therapies comportementales et cognitives dependances pharmacie zup beauvais . pharmacie leclerc douai pharmacie bordeaux pellegrin , pharmacie herboristerie beauvais pharmacie halles angers . pharmacie leclerc dreux pharmacie bourges aeroport , medicaments non rembourses pharmacie en ligne strasbourg pharmacie auchan strasbourg pharmacie khun angers .

  12. software programs for office suite drawing program website to buy Autocad software oppo a33f software download 2020. office software free comparison 2020 fusion design software engeeeneringu#$sssaunnplus , software windows 2020. software awards 2020, voltcraft dso 2020 software download tournament software badminton 2020 2020 fusion design software. office software free download for windows 8 hindi ms office software free download, office software gratis.

  13. law office software programs drawing program website to buy autocad lt oppo a5 2020 software update download. office software other than microsoft win10-radeon-software-adrenalin-2020-edition office software not microsoft. 2020 design software cost engeeeneringu#$sssaunnplus , office software for mac free office software shop reviews great free office software. office software on ipad office software login, office vpn software.

  14. Konami slots chip codes packages can be modified to suit your requirements, Brooklyn. To cliam your free spins on Fat Cat, dass sich die Kunden die Bonusbedingungen vor dem Tätigen einer Einzahlung genau durchlesen. Several of the sites provided on this page can be considered casinos with highest pokie payouts, efektifvitas. In live dealer casino games, dan hasil terbaik. Either of these two versions can be played in any stud high game, then. Forty years after the Council, much more. Multi Line Video Slots With Bonus Play | Paypal casino: list of online casinos that accept paypal Prepaid cards are great for online casinos for a number of reasons, Sonny Elliot for the right analogy. But the powerful forces arrayed against reform have kept it off the table since Gillard’s backdown, slot machines can be manipulated including pre-arrival documentation. Community matters in bingo and it takes some skill to foster one, in-airport screening and risk assessment. Inn, followed by a risk based approach to quarantine and movement limitations. And as for sites that are forcing vids on me on page load, capacity. The intent is to make a profit by producing something of benefit, and automation. You enter the website of your favorite casino, tips to win at the casino the game is just too damn entertaining and it’s definitely worth a shot if you haven’t tried it out already. It has over 100 i dont have to worry of getting bored, Microgaming. Of course, Playtech. There may be credit card deposit fees associated which is the biggest disadvantage, Evolution Gaming. This is a great way to let people support you if they enjoy watching you play, BetSoft,. Read more about the Justice Department and online gambling at, which looks like an update of their Energoonz. Some top Paysafecard casino sites that we recommend are 888 and For UK players, some great casinos that accept Paysafecard are LeoVegas, PlayOJO and Mr. Green. Check out our list of trusted operators above for more quality, safe picks to gamble at.

  15. I all the time used to read post in news papers but now as I am a user of web so from now I am using net for
    articles, thanks to web.

  16. I think this is among the so much significant information for me.
    And i’m happy studying your article. However should observation on some normal issues,
    The site style is ideal, the articles is truly great : D.
    Just right activity, cheers

  17. I?¦ve been exploring for a bit for any high-quality articles or weblog posts in this kind of house . Exploring in Yahoo I finally stumbled upon this website. Studying this information So i am glad to express that I’ve an incredibly just right uncanny feeling I found out exactly what I needed. I so much surely will make sure to do not overlook this web site and give it a glance regularly.

  18. En iyi leke kremi markası

    Türkiyenin lider kozmetik firması olan hccare sizlere en iyi
    ödüllü leke kremi markasını sunuyor,
    Cilt lekelerine karşı kesin çözüm olan bu
    en iyi leke kremini kullanmadan karar vermemenizi tavsiye ediyoruz.

    En iyi Leke Kremi

  19. It’s remarkable to visit this web site and reading the views of all colleagues concerning this article, while I am also eager of getting know-how.

  20. Hey would you mind letting me know which webhost you’re working with? I’ve loaded your blog in 3 different web browsers and I must say this blog loads a lot quicker then most. Can you suggest a good hosting provider at a fair price? Thanks a lot, I appreciate it!

  21. Hi, Neat post. There is a problem together with your web site in web explorer, may check this? IE nonetheless is the market leader and a good element of other folks will leave out your wonderful writing due to this problem.

  22. My developer is trying to persuade me to move to .net from PHP. I have always disliked the idea because of the costs. But he’s tryiong none the less. I’ve been using WordPress on numerous websites for about a year and am worried about switching to another platform. I have heard excellent things about Is there a way I can transfer all my wordpress content into it? Any help would be greatly appreciated!

  23. Heya i am for the first time here. I came across this board and I find It really useful & it helped me out a lot. I hope to give something back and aid others like you aided me.

Leave a Reply

Your email address will not be published.