Myths about Marijuana

Font Size: + -

Feedback Print

Myth: Marijuana is "natural" so it's safe.
Fact: Just because marijuana comes from a plant doesn't mean it can't harm you. Marijuana has many negative health effects, including:

Can cause problems with attention, memory, and learning, and make problem solving harder
May raise blood pressure, can raise your heart rate, and may increase the chance of heart attack
Smoking marijuana leads to a greater risk of bronchitis, cough, and phlegm production
Increases risk of developing chronic mental disorders, including schizophrenia
Using marijuana during pregnancy is linked to lower birth weight, which can lead to developmental problems

The following links contain more detailed information on the health effects of marijuana:

Myth: Marijuana is not addictive.
Fact: A recent study found that 2.5% of US adults (nearly 6 million people) experienced marijuana use disorder in the past year, and 6.3% had experienced it at some point in their lives. People who begin using marijuana before the age of 18 are four to seven times more likely to develop marijuana use disorder than those who start using as an adult. About 1 in 10 marijuana users will become addicted; this increases to about 1 in 6 for those who begin using before the age of 18.

Marijuana users who are dependent on the drug experience withdrawal symptoms when not using the drug. Withdrawal symptoms include: irritability, mood and sleep difficulties, decreased appetite, cravings, and restlessness. Marijuana users who are addicted cannot stop using the drug even though it’s causing health and social problems in their life. There is currently no FDA-approved medication for the treatment of marijuana use disorder, but a number of behavioral treatments have been successful. Learn more about local substance use treatment programs here.

Myth: Driving while high is safe.
Fact: Driving under the influence of marijuana is unsafe and illegal. Marijuana negatively affects the skills you need to drive safely, including reaction time, coordination, and concentration, and increases the risk of a motor vehicle crash. Learn more about driving while high.

Myth: Marijuana cures disease.
Fact: In 2017, the National Academies of Sciences, Engineering, and Medicine published a rigorous review of scientific evidence on the health impacts of marijuana. They found that marijuana is effective for the treatment of chronic pain in adults, the treatment of chemotherapy-induced nausea and vomiting, and for improving patient-reported multiple sclerosis spasticity symptoms. There was little to no evidence that marijuana was effective in treating any other health conditions.

If you choose to use, use responsibly

Don't use marijuana around children and keep marijuana out of sight and reach of children and pets.

Kids and pets (and unsuspecting adults) can mistake marijuana products for regular food or candy. You can help prevent this by storing your products safely and securely.
Marijuana affects children more strongly than adults. Children are at higher risk for poisoning from marijuana, especially with edibles.
Don't smoke marijuana around children and pregnant women. Secondhand marijuana smoke contains THC (the chemical that makes you high) and other chemicals that can negatively affect health.
Dispose of leftover marijuana in a secured container and out of sight. Don’t leave it in the open or throw it on the ground where children and pets can get to it.
If your child accidentally consumes marijuana, call the Poison Center Hotline immediately at 1-800-222-1222. If symptoms are severe (e.g., difficulty walking or sitting up, excessive sleepiness, difficulty breathing), call 911 or go to the emergency room right away.
Call a veterinarian if you're worried about your pet.
Learn more about responsible use.

Know how much your body can handle and how much is too much

Marijuana affects everybody differently, and varying doses, strains, and forms can lead to different lengths and strengths of impairment.
The amount of THC (the chemical that makes you “high”) in marijuana has been increasing steadily over the past few decades because of the way cannabis plants are grown. The higher the THC content, the stronger the effects on your brain and behavior.
Carefully read the product label, which will tell you serving size (in Massachusetts, an individual serving size of any marijuana product cannot contain more than 5 mg of THC), cannabinoid profile, total amount of THC in the product, and directions for use.
Vaporized and concentrated marijuana can have a lot more THC, which increases the risk of poisoning.
If you smoke or vape marijuana, you may feel the effects right away, but it can take between 30 minutes and 4 hours to feel the effects of edibles. Edibles can also cause effects that last longer than expected. How edibles affect you depends on how old you are, your metabolism, the amount you eat, and medications or alcohol used at the same time.

Don’t combine marijuana with alcohol or medications

Using alcohol and marijuana at the same time will result in greater impairment than when using either one alone, and could also cause nausea, vomiting, panic, anxiety or paranoia, and hallucinations.
Marijuana may change how your medications work. Always talk with your health care provider about any medications you are taking and possible side effects when mixed with marijuana.

Don't use marijuana if you're pregnant, breastfeeding, or planning to get pregnant soon

The Centers for Disease Control and Prevention (CDC) recommends against using marijuana during pregnancy because THC will reach the fetus through the bloodstream and placenta and it may increase the baby's risk of problems with attention, memory, problem-solving skills, and behavior over the course of their lifetime.
THC in marijuana gets into breast milk and may affect your baby.
Learn more about marijuana and pregnancy.

Know when to call 911

A fatal overdose is unlikely. However, using high concentrations of THC can affect your judgment, perception, and coordination, and may lead to poisoning, injuries, and accidents.
The symptoms of using too much marijuana are similar to the typical effects of using marijuana, but more severe. These symptoms may include: extreme confusion, anxiety, paranoia, panic, fast heart rate, delusions or hallucinations, increased blood pressure and severe nausea/vomiting. If someone is having trouble breathing, has pale skin, or is unresponsive, call 911.

Last reviewed and updated April 2019

Free viewers are required for some of the attached documents.
They can be downloaded by clicking on the icons below.

Acrobat Reader