People often use alcohol and weed together. Both drugs have similar effects on the body and mind, including drowsiness, slowed reflexes, and changes in judgment and time perception.

Combining weed and alcohol can increase the effects of both drugs and cause adverse reactions. The combination can also lead people to engage in unusual or risky behaviors.

Not everyone reacts in the same way to weed, alcohol, or a combination of both, and many factors play a role in how a person will respond. However, it is helpful to understand the possible outcomes of mixing these drugs.

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A person may experience alterations in judgment when they mix weed and alcohol.

There is limited research available on the long-term effects of consuming alcohol alongside weed, which people also call marijuana or cannabis.

However, the body of existing research is likely to grow and evolve as more states begin to legalize marijuana use.

At present, the potential known outcomes of mixing weed and alcohol include the following:

Alterations in judgment

Both alcohol and weed can affect a person’s judgment. When people combine the two drugs, this effect may intensify. Their combined use can cause blackouts, memory loss, and an increased likelihood of engaging in risky behaviors.

Research indicates that people who mix alcohol and cannabis are more likely than those who only drink alcohol to engage in sensation seeking behavior.

Using alcohol and weed simultaneously also increases the chances of having unprotected sex with a partner, as well as other negative outcomes relating to legal issues, academia, and relationships.


Alcohol is a diuretic, which means that it causes people to produce more urine. Over several hours, this can lead them to become dehydrated, as they lose more fluid than they take in. Using alcohol and cannabis together could intensify this effect.

In rare cases, chronic marijuana use can result in cannabinoid hyperemesis syndrome, which causes severe nausea, vomiting, and dehydration.

Mental health problems

Research indicates that there is an association between frequent heavy alcohol use and poor mental health, including psychological distress and low life satisfaction.

In a 2018 resource document called Opposition to Cannabis as Medicine, the American Psychiatric Association caution that cannabis use may exacerbate or accelerate the onset of psychiatric illnesses.

The American Psychological Association suggest that adolescents’ developing brains are especially vulnerable to long-term damage from weed use.

Long-term physical health risks

Any form of drug misuse, especially in the long term, can lead to problems with the:

  • gastrointestinal system
  • heart
  • immune system
  • kidneys
  • liver

Reduced cognitive function

Marijuana use may contribute to cognitive decline, poor attention and memory, and lowered IQ, especially in the developing brain.

The long-term use of both alcohol and weed may cause structural changes in the brain, with a combination of these drugs leading to more prominent effects. Researchers have found that heavy weed users who drink alcohol have worse cognitive functioning than people who only consume alcohol.

Weed and alcohol together can also impair reaction times and other cognitive functions necessary for safe driving.

A 2013 study found that those who combined weed and alcohol showed consistently impaired driving performance during driving simulations. The results also showed that regular cannabis users displayed more driving errors than those who did not regularly use the drug.


The authors of a 2017 review suggest that people who use alcohol and weed together typically consume more of both drugs. This higher intake may increase the risk of dependence on alcohol, weed, or both.

A 2019 study supports this, finding that those who use alcohol and weed simultaneously are likely to drink more alcohol more frequently.


As with any drug use, there is the potential for overdose. As the research indicates, people who use both alcohol and weed together tend to consume more of both. High consumption rates increase the risk of overdose.

The order in which a person uses weed and alcohol may affect the outcome.

Smoking weed after drinking alcohol may intensify the effects of weed. The reason behind this is that alcohol increases the absorption of tetrahydrocannabinol (THC), which is the main psychoactive component in cannabis. People who smoke weed after drinking alcohol often experience a stronger high.

Some people, especially those who are not used to weed consumption, may experience a “green out.” A green out can cause intense and unpleasant symptoms, such as dizziness, sweating, nausea, and vomiting.

Increased THC absorption may also cause anxiety, panic, and paranoia.

Weed use before alcohol may slow down the rise in blood alcohol levels, which can reduce or delay the sensation of being drunk. However, this finding comes from older research, and some people have questioned this study.

If weed use does slow down the increase in blood alcohol levels, this may cause people to drink more than usual. In turn, this could increase risky behavior and the likelihood of alcohol poisoning.

Other forms of cannabis, including edibles, can also interact with alcohol to cause most of the same risks as smoking cannabis. Edibles are foods that contain marijuana or its active ingredients, such as THC.

There may be additional risks because it is easy to overconsume edibles. Even small amounts of edibles can produce strong highs, depending on the amount of THC and other cannabinoids that they contain.

Alcohol can also cause people to feel more hungry than usual, which may lead them to overindulge on edibles.

Individuals who are drinking alcohol and consuming edibles should carefully monitor what they consume. However, it is safer to avoid edibles entirely when drinking alcohol.

Using weed and alcohol together can intensify the effects of both drugs. It is safer to use either drug without the other, although the safest option is to use neither.

Individuals who choose to mix the two should keep track of how much alcohol and weed they consume.

Those who have concerns about their use of either or both drugs should speak to a doctor or call the National Drug Helpline on 1-844-289-0879.