Short answer
Mixing cannabis with an energy drink puts a stimulant and a cannabinoid in the body at the same time. THC raises heart rate and can trigger anxiety. Caffeine raises heart rate and blood pressure. Both push the heart in the same direction. CBD does not cause intoxication, but CBD can slow the liver's breakdown of caffeine. Human studies on the mix are thin. Keep doses low, or choose one product.
Caffeine content in energy drinks
Can sizes and caffeine loads vary by brand.
- Red Bull, 8.4 oz: 80 mg
- Monster Energy, 16 oz: 160 mg
- Rockstar, 16 oz: 160 mg
- Bang Energy, 16 oz: 300 mg
FDA cites 400 mg of caffeine per day as a level not linked to negative effects in healthy adults. One 16 oz can holds 40 to 75 percent of that number.
How the liver handles the pair
Caffeine is broken down by the enzyme CYP1A2. Lab tests show CBD blocks CYP1A2 and other CYP enzymes. That can extend the time caffeine stays in the body. THC and CBD are processed by CYP3A4 and CYP2C19. Caffeine competes for some of the same paths. The 2018 Epidiolex label lists CYP1A2 as one CBD target. Data on the size of this effect in humans is limited.
Heart rate and blood pressure
THC can raise heart rate by 20 to 50 beats per minute in the first hour. NIDA notes the cardiac effects can last 2 to 3 hours. Caffeine at 200 mg can raise systolic blood pressure by 3 to 8 mm Hg in people who use it rarely. Stack the two and the load adds up.
Sleep and next-day effects
Caffeine has a half-life of 3 to 7 hours. Half the dose stays in the body at hour 5 for many people. THC cuts REM sleep. The mix can leave a person tired and foggy the next morning.
Legal status in the US
Hemp CBD with less than 0.3 percent THC is legal at the federal level under the 2018 Farm Bill. THC drinks are legal in some states only. Rules differ by state. Check state law before buying.
Lower-risk approach
- Start with 2.5 to 5 mg THC, or 10 to 25 mg CBD.
- Cap caffeine at 200 mg for the day.
- Wait 2 hours between products to read the first effect.
- Drink water. Caffeine has a mild diuretic effect.
- Skip the mix with a heart condition, uncontrolled blood pressure, or use of CYP1A2 inhibitors such as fluvoxamine or ciprofloxacin.
When to skip it
Skip the mix if you take blood pressure drugs, heart rhythm drugs, or anxiety drugs. Skip it if you are pregnant or under 21. Skip it before driving. Caffeine masks some THC sedation. The impairment remains.