CESAR: Center for Substance Abuse Research



Marijuana, the most commonly used illicit drug in the United States, is taken from the leaves and flowering tops of the Cannabis sativa plant. It also comes in a more concentrated, resinous form, called hashish, and as a sticky black liquid called hash oil. The name "hemp" usually refers to low-THC varieties of cannabis that are grown for industrial uses (i.e., rope, clothing). According to the 2000 National Household Survey on Drug Abuse, an estimated 34% of Americans over the age of 12 have used marijuana in their lifetime.1 The average potency of the drug has increased substantially in the last twenty years, although it can vary significantly, depending on the type of plant and its origin. The main psychoactive chemical in the plant is THC (delta-9-tetrahydrocannabinol), although marijuana contains some 400 other chemicals as well.


Marijuana first became popular in the United States with Mexican immigrants in the 1920's and was quickly adopted by those in the jazz community. Later, the Great Depression of the 1930's led to a growing hostility toward the increase in marijuana use that was linked to immigration. The Marihuana Tax Act of 1937 placed control of the Cannabis plant into the hands of the federal government, which released very exaggerated portrayals of marijuana's effects (i.e., "Reefer Madness") and made the drug illegal. These stories, paired with the ban on private use, kept marijuana use fairly uncommon until the 1960's. After the "hippie" counterculture rediscovered marijuana in the 1960's, demand for, and use of, the substance grew until about 1978, when the favorable attitude toward the substance reached a peak. Since then, public attitudes have varied greatly from complete intolerance to ideas of legalization. In 1970, marijuana was listed as a Schedule I drug where it still remains today; however, the medical use of marijuana has been a hot topic for the last decade, along with the advent of synthetic forms of THC (i.e., Marinol).

Methods of Use

Various methods of smoking marijuana include rolling it into "joints" (marijuana cigarettes) or "blunts" (marijuana rolled into the leaf wrap of a hollowed-out cigar). Smoking through a pipe or bowl, through a waterpipe (or "bong"), or a vaporizer are also common methods. While marijuana is most often smoked, it can also be ingested. The drug can be ingested alone or cooked into food, most notoriously in "hash brownies." In addition, it can be used to brew tea or "bhang," a highly potent beverage originating from India. 3 The effects of smoking are typically felt within a few minutes and can peak in 10 to 30 minutes. Short-term effects from smoking generally wear off within 2 to 3 hours. And when eaten, the effects do not appear for 30 to 60 minutes, but can last up to 6 hours. 4 It is important to note, however, that the effects of the drug can be very different than expected if the marijuana has been laced with other drugs.

Laced Marijuana

One of the dangers of smoking marijuana is the possibility that it has been laced with another, more dangerous substance such as cocaine, crack, PCP, or even embalming fluid. Dealers have been known to sell joints, blunts, or cigarettes dipped in embalming fluid and laced with PCP. Though reports of laced marijuana are infrequent, and most lacing of marijuana is done at user-level, it is important to remember that with unregulated drugs such as marijuana, the user has no way of knowing what other types of substances have been added.

When individual users lace marijuana, they may sprinkle powdered cocaine or crack into a joint or blunt, combining the stimulant effects of cocaine with the depressant and hallucinogenic effects of cannabis. This can be very dangerous, especially for a person with not tolerance to cocaine. Users have also been known to snowcap bowlfuls of marijuana with powdered opium or heroin, in addition to cocaine and crack. Again, combining other drugs with marijuana can be extremely dangerous.

Smoking a joint that has been dipped in embalming fluid or formaldehyde has effects similar to those of a joint laced with PCP - a drug that causes hallucinations, euphoria, and often times, panic or rage. Having a negative reaction is even more likely if the user is expecting only the normal marijuana high. In addition to these psychological dangers, marijuana that has been laced is also extremely unhealthy. Formaldehyde is a known carcinogen linked to nasal and lung cancer, with possible links to brain cancer and leukemia, and should not be smoked or ingested in any way.

Physical Effects

When a person smokes or ingests marijuana, THC and other chemicals enter the user's body. The chemicals make their way through the bloodstream to the brain, where THC and the neurotransmitter anandamide bond to cannabinoid receptors. High concentrations of these receptors exist in those parts of the brain associated with short-term memory and reasoning, coordination, and unconscious muscle movements.5 These findings may explain the loss of short-term memory and coordination associated with heavy marijuana use. Marijuana also causes the user's heart rate to increase, the mouth to become dry (commonly referred to as "cotton-mouth"), blood vessels in the eyes to expand (producing bloodshot eyes), and can also cause the "munchies" the increase in appetite that many users experience.

Long-term marijuana use produces changes in the brain similar to those seen after long-term use of other drugs, and can cause behaviors such as uncontrollable drug craving, delinquent behavior, and aggression. Regular marijuana smokers also face some of the same problems as cigarette addicts, including daily cough and phlegm, symptoms of chronic bronchitis, and frequent chest colds. Because marijuana is usually smoked without a filter, the amount of carbon monoxide and tar inhaled by marijuana smokers is three to five times greater than that inhaled by tobacco smokers.

Psychological Effects

Many users describe two phases of the marijuana high: initial stimulation (giddiness and euphoria), followed by sedation and a pleasant tranquility. Users also report altered perceptions of distance and time along with a heightened sensitivity to sights and sounds. Effects can vary from person to person and can differ with each use. While some users may experience lowered inhibitions, drowsiness, and contentment, others may feel great anxiety and paranoia. And depending upon the user and setting, the effects and categorization of marijuana can vary from a stimulant to a depressant to a hallucinogen. Any of these effects can begin within a few minutes after inhaling, and can last 2 to 3 hours after initial intoxication.

Is Marijuana Addictive?

The debate between marijuana and addiction has been growing steadily over the last decade. Many users may not display any signs of addiction or withdrawal, yet the number of users seeking treatment has been growing steadily over the years.6 Overall, it is difficult to say whether or not the drug is physically addictive, but it is known that marijuana use can lead to psychological addiction and social dependence.7

Is Marijuana a "Gateway Drug?"

There has been a great deal of debate concerning the dangers of marijuana use. While its effects may be seen as benign when compared to other drugs, many believe that marijuana can often be the starting point for a person's experimentations with drugs. A recent study in New Zealand found that 99% of other illicit drug users had previously used marijuana.8 However, a majority of marijuana users studied (63%) did not progress to the use of other illicit drugs. There is still no conclusive evidence that marijuana is, in fact, a gateway drug, though it is clear that most illicit drug users have experimented with marijuana at some point in time. Although marijuana may not necessarily be a "gateway drug" for all users, its use constitutes engagement in risky behavior and may set a pattern for future behavior.

Short-Term Effects

A person who is high on marijuana might display some of these symptoms and signs of abuse:9

  • Dizziness or trouble walking
  • Acting silly and giggly for no reason
  • Red, bloodshot, or glazed eyes
  • Anxiety and paranoia
  • Difficulty remembering things that just happened
  • Disinterest in activities or other things he or she used to enjoy

Long-Term Effects

Long-term marijuana abuse has several negative impacts on the user, including:10

  • Limiting the brain's capacity to store and retrieve information
  • Damage to the brain's memory functions, as well as math and verbal skills
  • Sexual dysfunction and reproductive problems, including irregular sperm and lowered sperm count in men and menstrual and ovulatory disruption in women
  • Weakening of the immune system
  • Increased risk of cancer and lung damage
  • Increased blood pressure and risk of heart attack
  • Loss of motivation and interest in everyday activities and future plans

Cannabis Indica

Originally cultivated in the United States, Cannabis Indica, or "ganja" is taken from the tops of the female plant, and smoked as a form of marijuana. Indica plants are short, dense plants, with broader, darker green leaves than that of the Cannabis Sativa plant. It is commonly referred to as "skunk", (for the pungent odor it produces while growing), Northern Lights, Early Girl, and many other names. Many users substitute this drug for ecstasy or LSD, or use it in combination with these drugs. Frequently, the drug is mixed with tobacco and smoked.

Cannabis Indica and Cannabis Sativa produce two greatly different effects. Cannabis Sativa produces a "high" effect, while Indica produces a more relaxed, "stoned" effect. Indica contains a higher amount of THC, causing the psychological effects to be heightened. Labeled a class C drug, it has been approved by the FDA for the use of treating nausea in cancer patients, stimulating appetites in AIDS patients, and for the treatment of glaucoma.


There are many different methods through which users smoke. Marijuana that has been rolled into cigarette paper is referred to as a "joint," and can be rolled by hand or by a rolling machine. A "blunt" simply refers to a common cigar that is split open, emptied of tobacco, and refilled and rolled with marijuana. This term comes from Phillies Blunts, but other, similar, types of cigars are also commonly used, including White Owls, El-Productos, Backwoods, Garcia-Vegas, and Dutchmasters. Users also commonly smoke marijuana through hand-pipes made of glass or wood, and through waterpipes (bongs) made of glass or plastic. Water pipes allow the smoke to be filtered and cooled prior to inhalation, providing the user with larger, cleaner hits. Also, vaporizers supply another way of smoking marijuana, in which the drug is heated enough to vaporize the plant and release the THC, without the user having to inhale large amounts of smoke.


  • Slang Terms for Marijuana:
    Weed, Pot, Bud, Herb, Grass, Reefer, Ganja, Green, Mary Jane, Cheeba, Dope, Endo, Buddha, Smoke, Wheezy
  • Slang Terms for Marijuana Laced with Other Drugs:
    With PCP - Boat, Loveboat, Chips, Donk, Illies, Illing, Lovelies, Love Leaf, Killer Weed, Supergrass, Wack, Woolies, Zoom, Fry, Frios (Spanish), Yerba Mala (Spanish)
    With Formaldehyde (embalming fluid) - Boat, Loveboat, Fry, Amp, Drank, Clickem, Ill, Illy, Wack, Wet, Water-Water
    With Cocaine - Chronic, Banano, Caviar, Champagne, Cocoa Puff, Gremmies, Lace
    With Crack Cocaine - Chronic, Bazooka, Cocktail, Crack Back, Fry Daddy, Dirty, Geek, Gimmie, Juice Joint, Liprimo, Oolies, P-Dogs, Torpedo, Turbo, Woolies
  • Potency-Related Terms:
    Low-grade - Schwag, Dirt weed
    Mid-grade - Middies, Skunk
    High-grade - Kindbud, KB, Hydro (hydroponically-grown), Nugs, Trees, Dank, Sensimilla (Spanish for "without seeds"), Kif (crystals shaken off high-grade buds, pronounced "keef")
  • Use & Users:
    Blunt - L, L-P, Bob, Philly, Dutchie, Gars
    Joint - J, Jay, White-Boy
    Thai Sticks - bundles of marijuana soaked in hash oil
    Shotgun - inhaling smoke forced into one's mouth by another's exhaling, usually with a blunt
    Dusting - adding another, powdered drug to marijuana
    Clambaking/Hotboxing - having a marijuana session in a tightly enclosed space (i.e. - in a car with the windows rolled up)
    420 - "International Pothead Code" - time for smoking marijuana (4:20), date for marijuana holiday (April 20)
    Head Shop - a store that sells paraphernalia and smoking accessories
    Heavy user - Pothead, Weedhead, Airhead, Head, Stoner, Burnout, Fiend

  • Links


    1 ONDCP Marijuana Fact Sheet. http://www.whitehousedrugpolicy.gov/drugfact/marijuana/index.html. June 13, 2002.
    2 David F. Musto. (July 1991). "Opium, Cocaine and Marijuana in American History." Scientific American.
    3 HowStuffWorks Marijuana Guide. http://www.howstuffworks.com/marijuana.htm. June 13, 2002.
    4 InTheKnowZone Marijuana Information. http://www.intheknowzone.com/marijuana/index.htm. June 13, 2002.
    5 NIDA Marijuana Facts for Teens. http://www.drugabuse.gov/MarijBroch/Marijteenstxt.html. July 30, 2002
    6 Lynn Zimmer and John P. Morgan. (1997). Marijuana Myths, Marijuana Facts. New York: The Lindesmith Center.
    7 Narconon Marijuana Addiction Page. http://www.marijuanaaddiction.info/marijuana-information.htm. July 30, 2002.
    8 David M. Fergusson and L. John Horwood. (2000). "Does Cannabis Use Encourage Other Forms of Illicit Drug Use?" Addiction 95: 505-520.
    9 NIDA - Marijuana: Facts for Teens. http://www.drugabuse.gov/MarijBroch/teenpg9-10.html#Tell. July 15, 2002.
    10 American Council for Drug Education: Basic facts about marijuana.