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Health Services

Health Education

Alcohol, Tobacco, and Other Drugs

What is marijuana?

Marijuana is the most commonly used illicit drug in the United States. Marijuana is comprised of the flowers, stems, seeds, and leaves of the hemp plant Cannabis sativa. The main active ingredient in marijuana is delta 9 tetrhydrocannabinol (THC). The THC content in marijuana ranges from 1% to 8%. THC binds with certain protein receptors in the brain that ultimately leads to the “high” people experience with marijuana use. Users often report feeling relaxed or an elevation of mood.

Marijuana is smoked in a cigarette (joint), pipe, bong, or a blunt (a cigar from which the tobacco has been replaced with marijuana that is sometimes combined with other drugs). Marijuana can also be mixed in food or brewed as a tea. Other forms of marijuana include a concentrated, resinous form called hashish, and as a sticky black liquid called hash oil.

Street names for marijuana include: pot, herb, mary jane, chronic, weed, and hash.

What are the short-term consequences of using marijuana?

Dry mouth, dry eyes, and visible signs of intoxication, such as bloodshot eyes and puffy eyelids are common among users of marijuana.

Users of marijuana also may experience problems with memory and learning; distorted perception; difficulty in thinking and problem solving; loss of coordination; and dangerous impairment of driving skills. In addition, users may experience anxiety attacks or feelings of paranoia and increased susceptibility to infections. Increased heart rate also occurs in users of marijuana; and individuals with heart disease or high blood pressure may experience cardiac problems.

What are the long-term consequences of using marijuana?

Regular users of marijuana may experience physical and psychological withdrawal symptoms including irritability, restlessness, insomnia, nausea, and intense dreams.

Marijuana contains benzoyprene, a known human carcinogen; and the levels of tar and carbon monoxide are 3 to 5 times higher than in cigarette smoke. Long-term marijuana users, therefore, may experience respiratory problems similar to those of cigarette smokers. These include persistent coughing, symptoms of bronchitis, and more frequent chest colds.

Marijuana compromises the ability to learn and remember information by impairing the ability to focus, sustain, and shift attention. Marijuana use impairs short-term memory and decreases motivation to accomplish tasks. Short term memory impairment may last up to 4 weeks after use.

Long-term marijuana use can affect an individual’s fertility by suppressing the production of hormones that help regulate the reproductive system. Men may experience decreased sperm counts and erectile dysfunction. Women may experience irregular periods.

Marijuana is addictive for some people, and tolerance to it builds quickly meaning it takes more of the drug to feel the same effects.

Remember, marijuana is addictive!

Is marijuana illegal?

Marijuana and its use, possession, manufacture, and sale are illegal.

How do I know if I have a problem with marijuana?

Each person is different, but some warning signs are:

  1. More frequent use
  2. Needing larger doses to get the same effect
  3. Spending time thinking about using the drug
  4. Spending more money than you have on it
  5. Missing class or failing to finish assignments because of marijuana
  6. Finding that it’s hard to be happy without it
  7. Erratic or unpredictable behavior

Marijuana addiction is typically treated along with addiction to other drugs because marijuana is commonly used with other drugs. As with treatment of other addictions, cognitive behavioral intervention is often used to help a person determine their use triggers and develop coping strategies. Currently, no medications are available to treat marijuana addiction.

Where can I get help?

Join Together, a project of the Boston University School of Public Health, maintains a searchable database on treatment facilities so that you can find one convenient to you. Visit and click on "Find Help."