Trusted Content

The Dangers Of Using Alcohol And Marijuana

Isaac Alexis, M.D., AAMA, AMP-BC

Medically reviewed by

Isaac Alexis, M.D., AAMA, AMP-BC

March 12, 2019

Alcohol and marijuana are two of the most socially accepted drugs in America. Using these drugs together (“crossfading”), however, is more dangerous than using either individually and, combined, these drug’s effects can lead to illness, injury and in certain cases, death.

What Is Marijuana?

Legal in a handful of states, marijuana (cannabis) is the most commonly abused illicit drug in our nation. A naturally occurring drug which comes from the cannabis plant, it’s most commonly smoked. Some users choose to vaporize it, eat it within food or drink it as a tea.

Marijuana has mind-altering properties which lead to a “high,” enhanced senses and variable moods. These shifts are due to the chemical tetrahydrocannabinol, more commonly known as THC.

Understanding Alcohol

Most people are familiar in some manner with alcohol. Small doses cause relaxation and pleasurable effects. Even though alcohol use is a commonplace practice within many social groups, it’s still a drug. Like other drugs, alcohol exposes the user to an array of adverse health effects and dangers.

Alcohol is a depressant, that is, it slows down your brain’s functioning and central nervous system (CNS). When consumed to excess, these functions plummet so low that a person’s life can be jeopardized. This is called alcohol poisoning, a severe form of overdose which can cause coma, brain damage and death.

Why Do People Use These Drugs Together?

Like the majority of polydrug abuse, people typically use these drugs together to increase the pleasurable effects of one or both of the drugs. Many users claim that this combined use yields a unique high. Dangerously, the way these drugs interact and affect a user is widely unpredictable and variable.

Research and anecdotal reports both suggest that the order by which you use the drugs may influence the side effects you’ll experience. Typically, it’s thought that if you use marijuana first, the side effects are less pronounced. Conversely, drinking alcohol prior to marijuana increases certain ill effects.

virtual care

Get treatment when
and how you need it.

Now just to be clear, when we say separately, it’s important to realize that these drugs are still essentially being used together. That is, the two doses are taken close enough in succession that the drugs are both present within your system at the same time.

How Do These Drugs Affect You Together?

Many of the side effects of alcohol and marijuana are the same. Both can drop your guard by:


  • Balance
  • Concentration
  • Coordination
  • Judgement
  • Memory
  • Problem solving skills
  • Reaction time
  • Thinking


  • Alertness
  • Inhibitions

Abusing these drugs at the same time increases these side effects, all of which lead to other serious risks.

How Are Alcohol And Marijuana Dangerous When Used Together?

Even though many people think of both alcohol and marijuana as social, party drugs, the results of crossfading aren’t always pleasurable and carefree. Dangers include:

Accidental Injury: When a person’s coordination and balance are off, they’re far more apt to slip, fall or even drown. Impaired judgement also makes it more likely for a person to engage in risky behaviors. Subsequently, poor reaction time could result in great bodily harm or injury to themselves or others.

Alcohol Poisoning: Marijuana clouds your mind, making it harder to make a sound, rational decision. Because of this, a person may drink to excess, to the point where their blood alcohol concentration (BAC) reaches dangerous levels.

When alcohol reaches these toxic levels in your body, its response is to expel the substance out of its system by vomiting. Marijuana is an antiemetic, meaning it suppresses your body’s ability to vomit.

While this may seem like a good thing, in this instance it’s anything but. If you’re not able to vomit, the alcohol remains in your stomach. This means your body continues to absorb it, potentially allowing it to reach fatal levels.

Altered Brain Development: Your brain continues to develop until you are in your early to mid-twenties. Prior to this, your brain is far more susceptible to damage. Research is ongoing on the exact ways that this combination may cause cognitive and brain dysfunction. However, individually, each drug has been linked to certain forms of cognitive decline and structural changes within the brain.

Cardiac Complications: Marijuana temporarily increases your heart rate. As we’ve discussed, alcohol decreases your heart rate. Used together, your heart is caught in a tug-of-war between these opposing actions. This can stress your heart, especially for those with preexisting cardiac concerns. Both drugs have also been connected to a higher likelihood of heart attacks.

Disrupted Child Development: Alcohol use during pregnancy is heavily linked to birth defects and other problems regarding the baby’s development. The National Institute on Drug Abuse writes that marijuana use during this time may cause “lower birth weight and increased risk of both brain and behavioral problems in babies.” Like alcohol, tentative findings suggest that marijuana can be excreted into breast milk in a way which could affect the child’s developing brain. Using both of these drugs during pregnancy places your child in even greater danger.

“Greening Out”: Marijuana can, by itself, cause a person to become severely nauseous and dizzy to the point of vomiting. Drinking alcohol prior to smoking marijuana increases the chance of this happening. Some research suggests that alcohol causes certain blood vessels to open more fully, allowing the THC to absorb faster. This intensifies your high into what can be uncomfortable extremes.

Impaired Driving: According to The American Journal on Addictions, when a person uses marijuana they struggle more frequently to perform “highly automatic driving functions,” whereas alcohol abusers fail at “more complex tasks that require conscious control.” In the case of the former, the driver often implements certain behavioral strategies in an attempt to overcome their impairment.

The findings continue to say that “Combining marijuana with alcohol eliminates the ability to use such strategies effectively, however, and results in impairment even at doses which would be insignificant were they of either drug alone.” Essentially, the combined effects of these two drugs inhibit both forms of functioning, effectively rendering the driver significantly impaired. To put this in a more concrete form, NIDA reports that “after alcohol, marijuana is the drug most often linked to car accidents, including those involving deaths.”

Mental Health Concerns: Both of these drugs may worsen existing mental health disorders. Additionally, research suggests that marijuana, like alcohol, is linked to depression, anxiety, and for teens, suicidal thoughts, as cautioned by NIDA.

Unsafe Sexual Practices: As both drugs decrease inhibitions and judgement, a person may engage in unprotected sex. This may lead to unplanned pregnancies and/or sexually transmitted diseases, including HIV/AIDS.

Sexual Assault And Rape: A person’s control over their judgement and coordination drop while they’re under the influence of these two drugs. In certain circumstances this can increase the risk of a person falling prey to sexual assault and rape.

In order to prevent these and other risks, we strongly urge you to seek treatment and help today.

Take Control Over Your Addiction And Your Life

At, we believe in the power of individualized treatment. Just as every individual who comes to us is different, so are their treatment needs. If you’re battling alcohol and marijuana, we can help you to develop a treatment plan which addresses both types of abuse. Contact us today.

NIDA - Drug Facts: What is marijuana?


Want to get help, but not ready to talk?

You can receive 24/7 text support right away and at your convenience. There is no obligation to enter treatment and you can opt out at any time.

Sign up for text support to receive:

✅ Resources about addiction and recovery

✅ Info about our treatment process

"*" indicates required fields


Let Regard Healthcare walk you through the treatment process. We're here to help.
For 24/7 Treatment Help
100% Free and Confidential. Call 888-341-4325

For 24/7 Treatment Help Call:


For Immediate Treatment Help Call:
(888) 979-9592