Cannabis can be used in several ways: 

• Smoked in joints (hand-rolled cigarettes)

• Blunts (emptied cigars or cigar wrappers partially or entirely refilled with cannabis)

• Bongs (pipes or water pipes)

• Blended or infused into foods such as cookies, cakes, brownies, candies (known as edibles), and drinks, like tea

• Electronic vaporizing devices (e-cigarettes or vape pens) or other vaporizers to avoid breathing smoke

• Dabbing is the practice of smoking cannabis plant oils, concentrates, and extracts

These articles highlight how to read a cannabis package: 

1. The Philadelphia Inquirer

2. Rise Cannabis

Note: It’s important to understand how to read labels so you can find a product that is safer for you.

Sources: National Institute on Drug Abuse

Cannabis use may have a wide range of effects, both physical and mental. Every person can experience different effects with variation in intensity and duration.  

How cannabis affects a person depends on several factors:

• Amount taken
• Frequency of use
• Use with other substances (e.g., alcohol or other drugs), which could increase risk of harm
• Mode of use (e.g., consuming edibles or products with high THC concentration can have delayed or unpredictable effects and increases the risk of overdose or poisoning)
• Previous experience with cannabis or other drugs
• Biology (e.g., genes, DNA)
• Sex (e.g., women or people assigned female at birth may experience more dizziness after using cannabis compared to men or people assigned male at birth)

Physical Effects:

• Breathing problems. 
• Cannabis smoke irritates the lungs, and people who smoke cannabis frequently can have the same breathing problems as those who smoke tobacco.
• Increased heart rate. 
• Cannabis 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. 
• Intense nausea and vomiting. 

Mental Effects:

• Temporary hallucinations
• Temporary paranoia
• Worsening symptoms in patients with schizophrenia—a severe mental disorder with symptoms such as hallucinations, paranoia, and disorganized thinking.

Linked to other mental health problems, such as depression, anxiety, and suicidal thoughts among teens. However, study findings have been mixed.

Sources: Centers for Disease Control (CDC), National Institute on Drug Abuse

Short-term effects:
When a person smokes cannabis, 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. 

Cannabis 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)

Sources: National Institute on Drug Abuse

Longer-term effects 
Recent studies have shown that Cannabis affects brain development. When people begin using cannabis as teenagers, the drug may impair thinking, memory, learning functions, and affect how the brain builds connections between the areas necessary for these functions. Researchers are still studying how long these effects last and whether some changes may be permanent.

Sources: National Institute on Drug Abuse

Cannabis 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. Research suggests that between 9-30% of those who use cannabis may develop some degree of marijuana use disorder. People who begin using cannabis before age 18 are four to seven times more likely than adults to develop a marijuana use disorder.

It’s important to note that, “high potency” cannabis is considered to be anything over 10% THC. Use of high potency cannabis is associated with a number of outcomes, including greater risk of cannabis use disorder and adverse mental health outcomes.

Source: National Institute on Drug Abuse

Common signs of a cannabis use disorder:

• Using more cannabis than intended
• Trying but failing to quit using cannabis
• Spending a lot of time using cannabis
• Craving cannabis
• Using cannabis even though it causes problems at home, school, or work
• Continuing to use cannabis despite social or relationship problems.
• Giving up important activities with friends and family in favor of using cannabis.
• Using cannabis in high-risk situations, such as while driving a car.
• Continuing to use cannabis despite physical or psychological problems.
• Needing to use more cannabis to get the same high.
• Experiencing withdrawal symptoms when stopping cannabis use.

Are you a Brown student interested in speaking to a Health Educator about your substance use? Request an Alcohol and Other Drugs (AOD) education appointment to discuss your current and potential future use, questions, and concerns. 

Sources: Centers for Disease Control (CDC), National Library of Medicine

If you are concerned about a friend's drug or alcohol use, this page contains information about different ways to help them.