Marijuana is a shredded, green-brown mix of dried flowers, stems, and leaves from
the plant Cannabis sativa. A stronger form of marijuana, called hashish (hash), looks
like brown or black cakes or balls. The amount of THC (the active ingredient) in marijuana
and marijuana products has increased greatly over the years.
Marijuana is usually rolled and smoked like a cigarette (joints or doobies), or
put in hollowed-out cigars (blunts), pipes (bowls), or water pipes (bongs). Recently,
it has become increasingly popular for people to inhale marijuana or stronger marijuana
extracts using a vaporizer (called "vaping" or "dabbing"). Some people mix it into
food or brew it as a tea.
There is also "synthetic marijuana" — manmade drugs that are chemically similar
to THC — that can be dangerously strong. Names for these drugs include "K2,"
"Spice," and "Herbal Incense." They can be so potent that overdose deaths
The main active chemical in marijuana is THC (delta-9-tetrahydrocannabinol). When
someone smokes marijuana, THC goes from the lungs into the bloodstream. From there,
it ends up in the brain and other organs.
THC connects with a receptor on nerve cells in the brain. The marijuana "high"
results from THC's effects on the nerve cells that control sensory perception and
THC also connects with receptors on nerve cells in other parts of the brain that
affect thinking, memory, coordination, and concentration. This can cause unwanted
side effects, including:
trouble thinking and problem solving
problems with memory and learning
loss of coordination
These side effects are temporary, but they can make it dangerous to do things like
drive while under the influence of marijuana.
People also might notice other short-term side effects of using marijuana, such
an increased appetite
feeling lightheaded or drowsy
a decrease in inhibitions
Research has found that people who use marijuana over a long period of time can
have more lasting side effects. For example:
Changes in the brain. Marijuana can affect the parts of the brain
that play a role in our ability to remember, multitask, and pay attention.
Fertility issues. Animal studies suggest that using a lot of marijuana
might be linked to decreased sperm count in men and delayed ovulation in women. Pregnant
women who use marijuana might be more likely to have babies with developmental and
Respiratory problems. People who smoke marijuana a lot can develop
problems with the respiratory system — like more mucus, a chronic cough, and
Immune system problems. Using marijuana a lot might make it harder
for the body to fight off infections.
Emotional problems. People who use a lot of marijuana are more
likely to say they notice signs of depression
or anxiety. If someone has
a condition like schizophrenia or bipolar
disorder, marijuana can sometimes make symptoms worse.
Here are a few ways marijuana use could affect you:
Criminal charges. Marijuana laws can be confusing. Some states
are changing their laws to make it legal to have small amounts of marijuana in some
situations (like when it's prescribed for medical use). Some have even made recreational
use of marijuana by adults (over 21) legal. But there are conflicting federal laws
against using, growing, or selling marijuana — and people caught with it could
face charges, including jail time.
Career problems. People charged under marijuana laws may end up
with criminal records that hurt their plans for college or finding a job.
Drug testing. These days, employers often test for drug use as
part of the hiring process. Marijuana can show up on a drug test for several weeks
after it was last used. So people who use marijuana may find they don't get a job
they want. Some companies do routine drug tests on employees, so people who use marijuana
can lose their jobs.
Medical Use of Marijuana
The U.S. Food and Drug Administration (FDA) has approved pills containing THC or
other cannabinoids (chemicals similar to THC) as a way to help relieve pain, nausea,
muscle stiffness, or problems with movement. There's still a lot of discussion about
the medical use of marijuana, though. THC and other cannabinoid pills are only available
in some states and require a doctor's prescription.
At the moment, there's not enough research to say for sure if smoking marijuana
is any more helpful than taking THC or other cannabinoids as a pill. Scientists are
still studying this.
What If I Want to Quit?
People who use marijuana for a while can have withdrawal symptoms when they try
to give it up. They may feel irritable, anxious, or depressed; have trouble sleeping;
or not feel like eating.
Marijuana withdrawal can be a bit like caffeine withdrawal: It's usually worse
a day or two after someone stops using marijuana. After that, withdrawal symptoms
gradually decrease. They're usually gone a week or two after the person no longer
uses the drug.
Marijuana can be addictive. About 1 in 10 people who use the drug regularly can
develop a "marijuana use disorder." These people can't stop using marijuana even though
it causing problems in their lives. This is much more likely to happen in people who
start using marijuana before age 18.
If you or someone you know wants to stop using marijuana but has trouble quitting,
it can help to talk to a counselor. Studies suggest that a combination of individual
counseling and group therapy sessions is the best approach for stopping marijuana