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Interaction of Alcohol and Marijuana: Effects and Risks of Joint Use

Both weed and alcohol are commonly used substances, especially among youth. It is important to understand how these substances interact and affect the body when used together. The interaction of alcohol and marijuana simultaneously can intensify the effects of both, increasing risks.

When alcohol, a depressant, is mixed with marijuana, a psychoactive drug, the two substances affect the body and mind in complex ways. Alcohol speeds up the absorption of THC, the main psychoactive component in marijuana. This leads to faster, more intense, and more unpredictable effects than using either substance alone.

Mixing these substances makes overconsumption and alcohol poisoning more likely. Long-term risks may include increased risk of addiction and mental health side effects. Understanding how alcohol and marijuana interact can help inform safe, responsible use. This article provides an overview of current research on the effects of mixing weed and alcohol.

Interaction of Alcohol and Marijuana

How THC and Alcohol Affect Each Other

Alcohol and marijuana both affect the brain and body when used alone. Combining them amplifies those effects and increases health risks.

Effects of Alcohol and Marijuana on the Body


Alcohol acts as a depressant on the central nervous system, slowing down brain activity. Short-term effects include impaired coordination, emotional swings, and loss of inhibition. Long-term heavy alcohol use can severely damage the liver, heart, and brain, increasing the risk of dementia and cancer.


Marijuana contains THC that stimulates brain cells, leading to euphoria and changes in sensory perception. Short-term effects include impaired memory, coordination, and reaction time. Long-term heavy marijuana use may impact brain development in teens and increase the risk of mental health issues.

Comparing Key Effects

A table comparing some effects of alcohol and marijuana:

Effect Alcohol Marijuana
Brain/Cognition Impaired coordination, emotional control, and judgment. Long-term risk of dementia. Impaired memory, learning, and coordination. Long-term mental health risks.
Body/Physiology Liver damage, cancer, and heart disease from long-term use. Lung irritation from smoking. Impaired immune system.

When used together, alcohol and marijuana can interact in the body, intensifying each other’s effects.

Mixing Alcohol and Marijuana

When alcohol and marijuana are used together, they interact in the body, amplifying each other’s effects. This can lead to greater impairment and increased risks compared to using either substance on its own.

How Alcohol and THC Interact in the Body

  • Both alcohol and THC (the psychoactive compound in marijuana) are processed by the liver. Using both together can increase the strain on this vital organ.
  • THC and alcohol affect some of the same receptors and pathways in the brain related to coordination, movement, and cognition. Their combined influence on these pathways results in more significant impairment than either drug alone.

Synergistic Effects of Combining the Two Substances

  • Enhanced sedation and loss of inhibition. The relaxing effects of both substances are compounded, resulting in greater drowsiness, loss of restraint, and reduced ability to function safely.
  • Increased heart rate and changes in blood pressure. Together, alcohol and marijuana can cause more erratic changes in circulatory function.
  • Worsened cognitive deficits and psychomotor impairment. Joint use exacerbates issues with reaction time, decision-making, memory, and concentration.

In summary, simultaneously using alcohol and marijuana results in amplified synergistic effects due to their combined influence on brain function. This increases risks and harms to both mental and physical health and safety.

Risks and Consequences of Mixing Alcohol and Marijuana

Greening Out

Greening out refers to experiencing unpleasant physical and psychological symptoms after consuming marijuana, particularly when combined with alcohol. Common symptoms of greening out include:

  • Nausea, vomiting
  • Dizziness, loss of physical coordination
  • Anxiety, panic attacks
  • Paranoia
  • Increased heart rate and blood pressure

The combination of marijuana and alcohol enhances the effects of both substances. This can lead to severe disorientation, loss of consciousness in extreme cases, and other dangerous symptoms.

Impaired Judgment and Decision-Making

Consuming marijuana and alcohol together impairs judgment, decision-making abilities, reaction time, and coordination. This increases the risk of accidents, injuries, and other unintended consequences of reduced mental faculty.

For example, the probability of reckless behavior such as drunk driving increases with marijuana-alcohol intake. Operating vehicles or machinery under the influence poses a major safety hazard. The impaired judgment also increases the likelihood of interpersonal conflicts or dangerous behavior.

Increased Risk of Accidents and Injuries

In addition to impaired cognitive abilities, mixing marijuana and alcohol can cause severe disorientation, confusion, and loss of balance or physical control. This vastly increases the chances of personal injury due to falls, accidents, or inability to respond appropriately to dangerous situations.

Potential for Alcohol Poisoning or Overdose

Using marijuana with alcohol is especially risky because both substances depress the central nervous system. Their effects compound each other to slow down breathing, heart rate, and other critical bodily functions. This increases the risk of alcohol poisoning, overdose, or loss of consciousness. The risk rises in a dose-dependent fashion with higher intakes.

In summary, simultaneously using marijuana and alcohol is highly dangerous due to amplified impairment of mental faculties and motor control. The combination also increases the risk of over-intoxication, accidents, and injuries. Exercising caution with these substances is strongly advised.

Comparing the Severity of Alcohol and Marijuana Use

Alcohol and marijuana are two of the most commonly used substances, often used together.

Effects on the Brain and Body

When used together, alcohol and marijuana produce greater impairment than either alone. Alcohol is a depressant while marijuana has biphasic effects, initially energizing but later causing relaxation. Using both can lead to greater confusion, drowsiness, and loss of coordination.

Addiction and Dependency Issues

Frequent mixed use can increase risks of addiction, tolerance to the substances, and withdrawal symptoms during abstinence. The sequence of use also matters — using marijuana before alcohol can increase alcohol intake, raising overdose risks.

Comparing the Severity of Alcohol and Marijuana Use

Is weed or alcohol worse? There are several factors to consider when comparing these substances:

  • Frequency of use: Daily heavy use of either substance is concerning and can indicate dependency or addiction issues.
  • Individual tolerance: The same quantity can affect people differently based on factors like body size, metabolism, and tolerance levels.
  • Long-term health consequences: Both substances carry risks like liver damage, cardiovascular disease, and certain cancers when used heavily over long periods. However, alcohol is linked to more direct overdose deaths and is arguably more destructive when abused.

Overall, both substances carry risks that increase when they are used together. More research is needed to definitively compare their severity. Avoiding heavy, frequent, or irresponsible use of either substance is advised.

Weed Drinks — An Alternative Approach

As an alternative to mixing alcohol and marijuana, some people are exploring marijuana-infused drinks, often called “weed drinks.” These beverages contain THC, the psychoactive compound in marijuana, dissolved into a liquid base. The idea is to provide a “high” through drinking rather than smoking.

Potential benefits of weed drinks:

  • Avoid the health risks of smoking
  • Precisely control THC dosage
  • Avoid mixing substances

However, weed drinks still come with risks:

  • Overconsumption can lead to marijuana overdose
  • Impaired coordination and decision-making
  • Possible long-term mental health effects

So while weed drinks may provide an alternative, moderation and responsible use are still extremely important. The key is being informed and setting reasonable limits for oneself.

For those struggling with substance abuse issues, whether involving alcohol, marijuana, or other drugs, support is available. Speaking to a doctor or counselor can help develop healthier coping strategies. There are always alternatives, and with the right help, more moderate and thoughtful approaches can be found.


The interaction of alcohol and marijuana is complex, with research showing that their combined use can heighten impairments and risks compared to using either substance alone. While popular culture often depicts mixing these substances as harmless fun, studies reveal elevated levels of intoxication along with impacts on motor skills, cognition, and behavior when weed and alcohol are combined.

Ultimately, any substance that alters consciousness carries individual and public safety hazards. No single guideline can determine universal risk or outcomes. Those choosing to use either or both drugs must educate themselves on how they interact physiologically and how impairment differs from person to person. Any use should be mindful and moderate. “Drunk vs. high” is a false dichotomy; both states alter functioning. Until more definitive research helps establish robust legal limits for marijuana, following alcohol control best practices with cannabis may help mitigate collective harm. Everyone’s health and well-being depend in part on the wisdom and care taken around potentially addictive substances.