BY BEN THOMAS | Original illustration for Ember by Simon Diago
Caffeine and cannabis have been popular partners since Amsterdam’s coffeeshops first started selling pre-rolls under the counter. Today, products like THC-infused tea, craft coffee, and cannabis-laced chocolate stirring spoons package that pairing even more artfully. But how well does a tea or coffee buzz pair with a cannabis high—and what does science have to say about how these chemicals interact?
Results seem to vary quite a bit. While some people say caffeine multiplies the energy and euphoria they get from THC, others find that the combination makes them “unbearably jittery”—at least, until they get the timing and dosage figured out. Scientific studies, meanwhile, have found that while low levels of caffeine can amplify THC’s effects, higher amounts can actually dampen your body’s ability to metabolize cannabinoids.
Here, we’ll take a closer look at why people pair these chemicals, and find out what to expect from a caffeine-powered cannabis experience.
People who enjoy waking up with “caffeine and green”—also known as the “hippie speedball”—say this pair naturally balance each other out. The caffeine provides a boost of energy to help start the day, while the CBD in the cannabis helps you settle in and focus on your work (or on binge-watching a new Netflix series). Tweak the balance a little, and you can reverse the timing, getting a nice mellow start to your workday, followed by a burst of focus to get you through those long hours before lunch.
Some fans of this pairing even say it helps them get into a flow state: a sense of effortless focus in which time and ego vanish, freeing you up for perfect absorption in the task at hand. Advocates of “waking, baking and brewing” swear by the unique balance of mellow alertness this combo produces—and when used in combination with exercise, a hippie speedball does seem to trigger a rush of brain chemicals often associated with flow states.
One of those key chemicals is dopamine, which brings us to the core of how caffeine and cannabis work together.
For people who relish that first uplifting rush from a sativa-dominant strain, caffeine can deliver an added boost, amplifying the chemical symphony’s most energizing notes. That’s because THC and caffeine both trigger the release of dopamine in our brains—but since they act on different neurochemical triggers, they can actually magnify each other’s euphoric effects. A 2017 study led by J.O. Owolabi at Babcock University confirmed that caffeine and cannabis team up in exactly this way, delivering a double dose of dopamine when they kick in together.
In fact, caffeine’s added dopamine boost may even prolong the effects of THC. In 2011, a team led by Zuzana Justinova, a psychiatric researcher at the University of Maryland School of Medicine, gave monkeys a small dose of caffeine, then offered them unlimited access to weed. Interestingly, caffeinated monkeys were much less interested in re-upping on THC after their first hits—which may mean caffeine prolonged the dopamine dance that kept them high.
But while it might sound great to double your dose of the world’s most famous “happy chemical,” the truth about dopamine isn’t quite so simple.
Although dopamine can trigger feelings of euphoria, it’s not just a “happy chemical.” This neurotransmitter also fuels many other intense emotions, both positive and negative—including feelings of agitation, hyper-vigilance, and even paranoia. This helps explain how “just one more hit” can sometimes turn a perfect high into a panic attack. It’s also a good reason to start small when adding caffeine to your THC mix, especially if you’re already prone to sativa-related nervousness.
Beyond their effects in the brain, caffeine and THC both speed up your heart rate, which can further amplify bodily feelings of anxiety. For this same reason, doctors say it’s not a great idea to mix cannabis and caffeine if you’re at risk for heart arrhythmia or stroke. Even people who thoroughly enjoy a cup of coffee as part of their wake-and-bake routine report experiencing “unsettling” “jittery” feelings during the first few days, until they zeroed in on the right dosage.
So if you’re new to combining cannabis and caffeine, the smart approach is to scale up slowly, until you’ve found a dosage mix that works for your unique body chemistry.
While there isn’t much research on the long-term effects of combining caffeine and THC, their double-dopamine euphoria rush does seem to come at a price. A 2018 study led by Marilyn Cornelis, associate professor of preventive medicine at Northwestern University’s Feinberg School of Medicine, found that the more coffee people consumed, the less cannabis their body metabolized. In other words, a high caffeine intake appears to make your nervous system less responsive to THC over time.
It’s also worth mentioning that, contrary to what you might expect, caffeine actually seems to worsen weed-related memory problems. A 2011 study led by Leigh V. Panlilio, a behavioral neuroscientist at the National Institutes of Health, found that the combination of caffeine and THC impaired rats’ working memory more than cannabis did on its own. While it’s true that rats aren’t people, psychoactive chemicals do affect their brains very similarly to ours. So even if caffeine and cannabis make you feel more focused, they may be doing the exact opposite: making you forget about all the things you’re forgetting.
To be clear, though, none of this is to say you shouldn’t (or should) mix caffeine and cannabis. All we’re doing here is summarizing the latest research—much of which is still preliminary—so you can make your own informed decisions.
In fact, some people say caffeine has elevated their cannabis experience to new levels. Beyond the euphoric buzz, aromatic chemicals called terpenes—famous for lending many weed strains their distinctive scents—can enhance the flavor profile of a cup of craft coffee or whole-leaf tea, inviting exploration of whole new realms of complementary pairings.
As with so many aspects of cannabis, you’ll have to discover what works for you—and isn’t that what makes the journey itself so fascinating?
Ben Thomas is a journalist and novelist who's lived in 40+ countries. He specializes in telling stories from the frontiers of science, history, culture, and the cosmos—and the points where all these fields intersect. Find him on Twitter at @writingben.