Alcohol and cannabis are two of the most popular substances in the UK, with around 75% of adults in the UK drinking alcohol whilst 6.5% of people aged 16 to 59 used cannabis last year.
Though seen as not a dangerous activity, mixing alcohol and weed can make the effects of both substances stronger and produce unpredictable effects. This mix can especially increase the risks of poor judgement, coordination, nausea, anxiety and a higher chance of accidents.
What Happens When You Mix Alcohol and Cannabis?
Both substances can have impacts on your brain; alcohol slows everything down whilst cannabis can alter your mood and thinking. This can result in effects on your perception, reaction time and coordination.
The effects can combine, becoming more impairing than if you were taking the substances alone, with studies finding that this is the case and intoxication was worsened when both were used at the same time.
How you react to the combination can’t be predicted. Reactions will vary depending on the potency of the weed, quantity of alcohol and weed you have, individual tolerance and how the cannabis was consumed.
Does Alcohol Make the Cannabis High Stronger?
There is some evidence that alcohol may increase or intensify exposure to THC if you drink before consuming cannabis. This could be because alcohol widens your blood vessels, meaning that THC is broken down more slowly in your body, boosting the effects.
When this happens, you get a more powerful experience.
The effects you experience are unpredictable, changing from time to time, so there is no research that can support a precise prediction for how the combination would affect you.
Short-Term Side Effects
While it can be hard to predict how you will be affected, there is a broad range of side effects you are likely to experience.
Common short-term side effects of alcohol and cannabis include:
- Dizziness
- Drowsiness
- Confusion
- Poor coordination
- Impaired memory
- Reduced concentration
- Delayed reactions
Sometimes, you may experience a severe reaction known as “whitey” or “greening out.” This can be unpleasant, bringing on side effects such as nausea, vomiting, sweating and faintness.
Anxiety, Paranoia and Panic
THC may trigger anxiety or paranoia in some people, with a study by the University of Oxford finding that 1 in 5 participants in their study had an increase in paranoia directly linked to THC.
These effects can be more severe due to the presence of alcohol, which lowers your inhibition, judgement and thinking, so paranoia and anxiety can be hard to manage, causing panic. This may lead you to experience more severe symptoms such as confusion, agitation and hallucinations.
If you believe that someone you are with may be an immediate risk to themselves or others, get urgent help and call 999.
Increased Risk of Accidents
Both substances will impair your judgement and coordination. This increases the risks of falls, road accidents, drowning and any type of injury you may not usually sustain with a clear head.
A recent study found that combined use of alcohol and weed significantly increased driving impairment, compared with if they were used separately. In many cases, people may be unaware of how affected they are, thinking it is a more harmless combination than alcohol and opioids.
You should not drive, cycle or operate machinery if you are under the influence of these substances separately or combined.
Can Mixing Weed and Alcohol Cause an Overdose?
A fatal overdose due to cannabis is unlikely, but when you experience an acute reaction alongside drinking, this can lead to a serious medical emergency.
The substances can intensify each other, which leaves alcohol poisoning a real possibility. This, along with “greening out”, could cause you to vomit, suffer a serious injury or lose consciousness. If you lose consciousness and vomit, there is a risk of choking.
Though cannabis can’t mask intoxication, it can alter your perception, making it harder for you to realise how drunk you are. This can affect how much you drink, how you react to your intoxication and overall decision-making.
Even alone, cannabis can still cause medical emergencies, even if it is less likely to lead to a fatal outcome.
What to Do if Someone Has a Bad Reaction
Are there immediate steps you should take if someone is having a bad reaction to alcohol and weed?
You should:
- Stop any further substance use and remain with the person.
- Move them to a calm and safe environment if you can.
- Call 999 if they are experiencing symptoms such as:
- Unconsciousness
- Seizures
- Chest pain
- Breathing problems
- Repeated vomiting
- Severe confusion
- If they are unconscious but breathing, place them into the recovery position.
You should not:
- Give them coffee, put them in a cold shower or try to make them vomit.
- Make your own diagnoses without professional advice.
Long-Term Risks of Regular Combined Use
If you use both substances repeatedly over a long period of time, you risk building up a tolerance, which can lead to a physical dependence. Over time, this may evolve into a more serious cannabis and alcohol addiction.
Long-term use can impact all aspects of your life. It can lead to:
- Low mood and mood swings dictated by drinking and drug use
- Poor memory and cognitive function
- Disrupted sleep, leading to fatigue
- Less motivation
- Breakdown in relationships due to cannabis and alcohol use.
There is also the potential that this combination worsens anxiety, depression or psychotic symptoms in people already suffering from these issues.
Signs That Alcohol or Cannabis Use Is Becoming a Problem
Alcohol and cannabis misuse can cause a range of symptoms that affect all aspects of your life.
Common symptoms of these addictions include:
- Cravings
- Loss of control
- Unsuccessful attempts to cut down
- Needing alcohol and cannabis to socialise, sleep or cope with emotions
A big indication of substance abuse is the fact that you continue using harmful substances despite the effects they are having on your health, work, financial situation or relationships.
Even if you are not engaging in daily use of these substances or experiencing withdrawal, you can still be concerned about having an unhealthy relationship with substances. It’s better to act now rather than let your problem worsen, and it becomes harder to end your substance use.
Getting Help for Alcohol and Cannabis Use
At rehab, your treatment for alcohol and cannabis use should deal with both substances simultaneously, rather than just focusing on one.
You may go through a medically assisted detox to end your physical dependence on these substances, leaving you in a healthier state to deal with the underlying issues. Psychological therapy, relapse prevention and support for co-occurring mental health issues will be critical to helping you learn healthier coping mechanisms, build strategies for long-term recovery and deal with the issues that led you to addiction.
If you are dependent on alcohol, withdrawal can be dangerous, so you should not stop drinking suddenly without getting clinical guidance.
Above is the type of treatment you should be aiming to find. At Action Rehab, we can help you find the right rehab for you, providing confidential advice and treatment-placement services.
Concerned About Mixing Alcohol and Weed? Talk to Our Team
Experiencing a bad reaction due to mixing alcohol and weed is a distinct possibility. Contact emergency services by calling 999 if you suspect that you or someone you know is having a severe reaction.
If you are concerned about your alcohol, cannabis or combined use, you don’t have to keep struggling on alone. Contact Action Rehab today for confidential advice on the next steps in your recovery journey.
Posted on Monday, September 28th, 2026 at 10:10 am in Addiction.
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