Mixing cannabis and alcohol raises your impairment above what either substance produces on its own. Alcohol increases the amount of THC your body absorbs, so the same edible or joint can hit harder than it would by itself. The pair also stacks dizziness, nausea, and slowed reaction time. If you plan to use both, keep the dose of each low, space them out by several hours, and do not drive.
cannabis and alcohol interaction
What the Research Shows
Cannabis and alcohol both slow the central nervous system, and both distort judgment. Research on co-use reports higher blood THC levels when alcohol enters the picture, along with a faster heart rate and more intense short-term memory loss. Emergency visits for "crossfading," the slang for the spinning, nauseated state that mixing can trigger, tend to cluster on weekends and holidays.
- Blood THC climbs when alcohol is consumed at the same time as cannabis or before it.
- Heart rate and blood pressure can swing in opposite directions.
- Reaction time and lane control get worse than after either substance alone.
- Nausea and vomiting become more likely, which matters more with edibles that are slow to peak.
How to Lower Risk If You Choose to Combine
Order and timing drive most of the risk. Work through these steps in sequence.
Combined Effects of Cannabis and Alcohol: What to Know
- Check your medication list with a pharmacist before you start, since sedatives, opioids, and some antidepressants interact with both substances.
- Choose one substance as the primary for the night and keep the other at a token amount.
- Pick the product with the lower dose, meaning a low-THC flower, a 2.5 mg edible, or a low-ABV drink.
- Consume the first substance and stop there for at least two hours.
- Cap the total for the night at one or two standard drinks and one low cannabis dose.
- Drink a full glass of water between every alcoholic drink.
- Eat a meal with protein and fat before the first dose to slow absorption.
- Arrange a ride home before you take anything.
- Skip the combination if you are alone, new to either substance, or under 21.
CBD and Alcohol
CBD does not cause the intoxication that THC does, but it is not inert when alcohol is in your system. CBD is processed by liver enzymes in the CYP450 family, the same group that handles alcohol and many prescription drugs. Large daily CBD doses can slow that enzyme activity and change how long other substances stay in the body. CBD also causes drowsiness in some people, which adds to alcohol sedation. There is no evidence that CBD sobers you up, prevents a hangover, or shields the liver from heavy drinking. The FDA has not approved CBD for alcohol use disorder. If you take CBD for sleep or anxiety, take it at a different time than your last drink.
Cannabis and Alcohol Interaction: What You Need to Know
When to Skip Both
- You are pregnant, breastfeeding, or under 21.
- You take opioids, benzodiazepines, sleep aids, muscle relaxants, or antihistamines.
- You have liver disease, a heart condition, or a history of fainting.
- You will drive or operate equipment.
- You have a history of alcohol or cannabis use disorder.
If Someone Feels Sick or Crossfades
- Stop all alcohol and cannabis use for the person.
- Move them to a seated or side-lying position so they cannot choke if they vomit.
- Offer small sips of water only while they are awake and alert.
- Give bland food such as crackers or toast if they can swallow.
- Keep the room dim, quiet, and warm, and stay with them.
- Call 911 if they cannot be woken, breathe slowly, or have chest pain, a seizure, or a racing pulse.
This is general information, not medical advice. Talk with a clinician about your own medications and health history before you combine cannabis and alcohol.